Joseph Heitman

αADα Hybrids of Cryptococcus neoformans: Evidence of Same-Sex Mating in Nature and Hybrid Fitness (2007)

Xiaorong Lin, Anastasia P. Litvintseva, Kirsten Nielsen, Sweta Patel, Anna Floyd, Thomas G. Mitchell, ...

Cryptococcus neoformans is a ubiquitous human fungal pathogen that causes meningoencephalitis in predominantly immunocompromised hosts. The fungus is typically haploid, and sexual reproduction...

Many Globally Isolated AD Hybrid Strains of Cryptococcus neoformans Originated in Africa (2007)

Anastasia P. Litvintseva, Xiaorong Lin, Irka Templeton, Joseph Heitman, Thomas G. Mitchell

Interspecific and intervarietal hybridization may contribute to the biological diversity of fungal populations. Cryptococcus neoformans is a pathogenic yeast and the most common fungal cause of...

Evolution of the Mating Type Locus: Insights Gained from the Dimorphic Primary Fungal Pathogens Histoplasma capsulatum, (2007)

Coccidioides Immitis, Coccidioides Posadasii, James A. Fraser, Jason E. Stajich, Eric J. Tarcha, Garry T. Cole, ...

Sexual reproduction of fungi is governed by the mating type (MAT) locus, a specialized region of the genome encoding key transcriptional regulators that direct regulatory networks to specify cell...

Recombination Hotspots Flank the Cryptococcus Mating-Type Locus: Implications for the Evolution of a Fungal Sex Chromosome (2006)

Yen-Ping Hsueh, Alexander Idnurm, Joseph Heitman

Recombination increases dramatically during meiosis to promote genetic exchange and generate recombinant progeny. Interestingly, meiotic recombination is unevenly distributed throughout genomes, and,...

Virulence Attributes and Hyphal Growth of C. neoformans Are Quantitative Traits and the MATα Allele Enhances Filamentation (2006)

Xiaorong Lin, Johnny C. Huang, Thomas G. Mitchell, Joseph Heitman

Cryptococcus neoformans is a fungal human pathogen with a bipolar mating system. It undergoes a dimorphic transition from a unicellular yeast to hyphal filamentous growth during mating and...

The cyclophilins (2005)

Wang, Ping, Heitman, Joseph

Abstract Summary Cyclophilins (Enzyme Commission (EC) number 5.1.2.8) belong to a group of proteins that have peptidyl-prolyl cis-trans isomerase activity; such proteins are collectively known as...

Light Controls Growth and Development via a Conserved Pathway in the Fungal Kingdom (2005)

Alexander Idnurm, Joseph Heitman

Two genes controlling light responses - BWC1 and BWC2 - were identified and shown to regulate development and virulence of the fungal pathogen Cryptococcus neoformans.

Light Controls Growth and Development via a Conserved Pathway in the Fungal Kingdom (2005)

Alexander Idnurm, Joseph Heitman

Light inhibits mating and haploid fruiting of the human fungal pathogen Cryptococcus neoformans, but the mechanisms involved were unknown. Two genes controlling light responses were discovered...

Convergent Evolution of Chromosomal Sex-Determining Regions in the Animal and Fungal Kingdoms (2004)

James A. Fraser, Stephanie Diezmann, Ryan L. Subaran, Andria Allen, Klaus B. Lengeler, Fred S. Dietrich, ...

A comparative genomic analysis of the sex determining region in fungi reveals a remarkable similarity between its evolution and the events which shaped mammalian sex chromosomes

Convergent Evolution of Chromosomal Sex-Determining Regions in the Animal and Fungal Kingdoms (2004)

James A. Fraser, Stephanie Diezmann, Ryan L. Subaran, Andria Allen, Klaus B. Lengeler, Fred S. Dietrich, ...

Sexual identity is governed by sex chromosomes in plants and animals, and by mating type (MAT) loci in fungi. Comparative analysis of the MAT locus from a species cluster of the human fungal pathogen...

Convergent evolution of chromosomal sex-determining regions in the animal and fungal kingdoms (2004)

Fraser, James A., Diezmann, Stephanie, Subaran, Ryan L., Allen, Andria, Lengeler, Klaus B., Dietrich, Fred S., ...

Sexual identity is governed by sex chromosomes in plants and animals, and by mating type (MAT) loci in fungi. Comparative analysis of the MAT locus from a species cluster of the human fungal pathogen...

Convergent evolution of chromosomal sex-determining regions in the animal and fungal kingdoms (2004)

Fraser, James A., Diezmann, Stephanie, Subaran, Ryan L., Allen, Andria, Lengeler, Klaus B., Dietrich, Fred S., ...

Sexual identity is governed by sex chromosomes in plants and animals, and by mating type (MAT) loci in fungi. Comparative analysis of the MAT locus from a species cluster of the human fungal pathogen...

A nomenclature for restriction enzymes, DNA methyltransferases, homing endonucleases and their genes (2003)

Roberts,Richard J., Belfort,Marlene, Bestor,Timothy, Bhagwat,Ashok S., Bickle,Thomas A., Bitinaite,Jurate, ...

A nomenclature is described for restriction endonucleases, DNA methyltransferases, homing endonucleases and related genes and gene products. It provides explicit categories for the many different...

A nomenclature for restriction enzymes, DNA methyltransferases, homing endonucleases and their genes (2003)

Roberts, Richard J, Belfort, Marlene, Bestor, Timothy, Bhagwat, Ashok S, Bickle, Thomas A, Bitinaite, Jurate, ...

A nomenclature is described for restriction endonucleases, DNA methyltransferases, homing endonucleases and related genes and gene products. It provides explicit categories for the many different...

A nomenclature for restriction enzymes, DNA methyltransferases, homing endonucleases and their genes (2003)

Roberts, Richard J., Belfort, Marlene, Bestor, Timothy, Bhagwat, Ashok S., Bickle, Thomas A., Bitinaite, Jurate, ...

A nomenclature is described for restriction endonucleases, DNA methyltransferases, homing endonucleases and related genes and gene products. It provides explicit categories for the many different...

A nomenclature for restriction enzymes, DNA methyltransferases, homing endonucleases and their genes (2003)

Roberts, Richard J, Belfort, Marlene, Bestor, Timothy, Bhagwat, Ashok S, Bickle, Thomas A, Bitinaite, Jurate, ...

A nomenclature is described for restriction endonucleases, DNA methyltransferases, homing endonucleases and related genes and gene products. It provides explicit categories for the many different...

A nomenclature for restriction enzymes, DNA methyltransferases, homing endonucleases and their genes (2003)

Roberts, Richard J., Belfort, Marlene, Bestor, Timothy, Bhagwat, Ashok S., Bickle, Thomas A., Bitinaite, Jurate, ...

A nomenclature is described for restriction endonucleases, DNA methyltransferases, homing endonucleases and related genes and gene products. It provides explicit categories for the many different...

Adenylyl Cyclase Functions Downstream of the Gα Protein Gpa1 and Controls Mating and Pathogenicity of Cryptococcus neoformans (2002)

Alspaugh, J. Andrew, Pukkila-Worley, Read, Harashima, Toshiaki, Cavallo, Lora M., Funnell, Deanna L., Cox, Gary M., ...

The signaling molecule cyclic AMP (cAMP) is a ubiquitous second messenger that enables cells to detect and respond to extracellular signals. cAMP is generated by the enzyme adenylyl cyclase, which is...

Novel Gbeta Mimic Kelch Proteins Gpb1 and Gpb2 Connect G-Protein Signaling to Ras Via Yeast Neurofibromin Homologs Ira 1 and Ira 2: A Model for Human NF1 (1998)

Heitman, Joseph, Harashima, Toshiaki

The Neurofibromatosis type 1 (NF1) gene encodes a large tumor suppressor protein, neurofibromin, which is a Ras GTPase-activating protein (RasGAP) activity. Although the NF1 gene was identified over...

Characterization of Alcohol-induced Filamentous Growth in Saccharomyces cerevisiae

Lorenz, Michael C., Cutler, N. Shane, Heitman, Joseph

Diploid cells of the budding yeast Saccharomyces cerevisiae starved for nitrogen differentiate into a filamentous growth form. Poor carbon sources such as starches can also stimulate filamentation,...

Protection from nitrosative stress by yeast flavohemoglobin

Liu, Limin, Zeng, Ming, Hausladen, Alfred, Heitman, Joseph, Stamler, Jonathan S.

Yeast hemoglobin was discovered close to half a century ago, but its function has remained unknown. Herein, we report that this flavohemoglobin protects Saccharomyces cerevisiae from nitrosative...

Identification of the MATa mating-type locus of Cryptococcus neoformans reveals a serotype A MATa strain thought to have been extinct

Lengeler, Klaus B., Wang, Ping, Cox, Gary M., Perfect, John R., Heitman, Joseph

Cryptococcus neoformans is an opportunistic fungal pathogen with a defined sexual cycle involving mating between haploid MATa and MATα cells. Here we describe the isolation of part of the MATa...

All cyclophilins and FK506 binding proteins are, individually and collectively, dispensable for viability in Saccharomyces cerevisiae

Dolinski, Kara, Muir, Scott, Cardenas, Maria, Heitman, Joseph

The cyclophilins and FK506 binding proteins (FKBPs) bind to cyclosporin A, FK506, and rapamycin and mediate their immunosuppressive and toxic effects, but the physiological functions of these...

Protein Kinase Activity and Identification of a Toxic Effector Domain of the Target of Rapamycin TOR Proteins in Yeast

Alarcon, Clara M., Heitman, Joseph, Cardenas, Maria E.

In complex with FKBP12, the immunosuppressant rapamycin binds to and inhibits the yeast TOR1 and TOR2 proteins and the mammalian homologue mTOR/FRAP/RAFT1. The TOR proteins promote cell cycle...

Functions of FKBP12 and Mitochondrial Cyclophilin Active Site Residues In Vitro and In Vivo in Saccharomyces cerevisiae

Dolinski, Kara, Scholz, Christian, Muir, R. Scott, Rospert, Sabine, Schmid, Franz X., Cardenas, Maria E., ...

Cyclophilin and FK506 binding protein (FKBP) accelerate cis–trans peptidyl-prolyl isomerization and bind to and mediate the effects of the immunosuppressants cyclosporin A and FK506. The normal...

The TOR Signal Transduction Cascade Controls Cellular Differentiation in Response to Nutrients

Cutler, N. Shane, Pan, Xuewen, Heitman, Joseph, Cardenas, Maria E.

Rapamycin binds and inhibits the Tor protein kinases, which function in a nutrient-sensing signal transduction pathway that has been conserved from the yeast Saccharomyces cerevisiae to humans. In...

Cyclic AMP-Dependent Protein Kinase Regulates Pseudohyphal Differentiation in Saccharomyces cerevisiae

Pan, Xuewen, Heitman, Joseph

In response to nitrogen starvation, diploid cells of the yeast Saccharomyces cerevisiae differentiate to a filamentous growth form known as pseudohyphal differentiation. Filamentous growth is...

The G-Protein β Subunit GPB1 Is Required for Mating and Haploid Fruiting in Cryptococcus neoformans

Wang, Ping, Perfect, John R., Heitman, Joseph

Cryptococcus neoformans is an opportunistic fungal pathogen with a defined sexual cycle. The gene encoding a heterotrimeric G-protein β subunit, GPB1, was cloned and disrupted. gpb1 mutant strains...

Cyclic AMP-Dependent Protein Kinase Controls Virulence of the Fungal Pathogen Cryptococcus neoformans

D'Souza, Cletus A., Alspaugh, J. Andrew, Yue, Changli, Harashima, Toshiaki, Cox, Gary M., Perfect, John R., ...

Cryptococcus neoformans is an opportunistic fungal pathogen that infects the human central nervous system. This pathogen elaborates two specialized virulence factors: the antioxidant melanin and an...

G Protein-coupled Receptor Gpr4 Senses Amino Acids and Activates the cAMP-PKA Pathway in Cryptococcus neoformansD⃞

Xue, Chaoyang, Bahn, Yong-Sun, Cox, Gary M., Heitman, Joseph

The Gα protein Gpa1 governs the cAMP-PKA signaling pathway and plays a central role in virulence and differentiation in the human fungal pathogen Cryptococcus neoformans, but the signals and...

Antifungal Activities of Antineoplastic Agents: Saccharomyces cerevisiae as a Model System To Study Drug Action

Cardenas, Maria E., Cruz, M. Cristina, Del Poeta, Maurizio, Chung, Namjin, Perfect, John R., Heitman, Joseph

Recent evolutionary studies reveal that microorganisms including yeasts and fungi are more closely related to mammals than was previously appreciated. Possibly as a consequence, many natural-product...

Comparison of In Vitro Activities of Camptothecin and Nitidine Derivatives against Fungal and Cancer Cells

Del Poeta, Maurizio, Chen, Shih-Fong, Von Hoff, Daniel, Dykstra, Christine C., Wani, Mansukh C., Manikumar, Govindarajan, ...

The activities of a series of camptothecin and nitidine derivatives that might interact with topoisomerase I were compared against yeast and cancer cell lines. Our findings reveal that structural...

Immunosuppressive and Nonimmunosuppressive Cyclosporine Analogs Are Toxic to the Opportunistic Fungal Pathogen Cryptococcus neoformans via Cyclophilin-Dependent Inhibition of Calcineurin

Cruz, M. Cristina, Del Poeta, Maurizio, Wang, Ping, Wenger, Roland, Zenke, Gerhard, Quesniaux, Valerie F. J., ...

Cyclosporine (CsA) is an immunosuppressive and antimicrobial drug which, in complex with cyclophilin A, inhibits the protein phosphatase calcineurin. We recently found that Cryptococcus neoformans...

Synergistic Antifungal Activities of Bafilomycin A1, Fluconazole, and the Pneumocandin MK-0991/Caspofungin Acetate (L-743,873) with Calcineurin Inhibitors FK506 and L-685,818 against Cryptococcus neoformans

Del Poeta, Maurizio, Cruz, M. Cristina, Cardenas, Maria E., Perfect, John R., Heitman, Joseph

Cryptococcus neoformans is an opportunistic fungal pathogen that causes life-threatening infections of the central nervous system. Existing therapies include amphotericin B, fluconazole, and...

Rapamycin and Less Immunosuppressive Analogs Are Toxic to Candida albicans and Cryptococcus neoformans via FKBP12-Dependent Inhibition of TOR

Cruz, M. Cristina, Goldstein, Alan L., Blankenship, Jill, Del Poeta, Maurizio, Perfect, John R., McCusker, John H., ...

Candida albicans and Cryptococcus neoformans cause both superficial and disseminated infections in humans. Current antifungal therapies for deep-seated infections are limited to amphotericin B,...

Cryptococcus neoformans Differential Gene Expression Detected In Vitro and In Vivo with Green Fluorescent Protein

Del Poeta, Maurizio, Toffaletti, Dena L., Rude, Thomas H., Sparks, Sara D., Heitman, Joseph, Perfect, John R.

Synthetic green fluorescent protein (GFP) was used as a reporter to detect differential gene expression in the pathogenic fungus Cryptococcus neoformans. Promoters from the C. neoformans actin, GAL7,...

Comparison of the Roles of Calcineurin in Physiology and Virulence in Serotype D and Serotype A Strains of Cryptococcus neoformans

Cruz, M. Cristina, Sia, Rey A. L., Olson, Michael, Cox, Gary M., Heitman, Joseph

The calcineurin gene was cloned and disrupted in serotype D strains of Cryptococcus neoformans. Serotype A and serotype D calcineurin mutants were inviable at 37°C and avirulent in mice, whereas...

Serotype AD Strains of Cryptococcus neoformans Are Diploid or Aneuploid and Are Heterozygous at the Mating-Type Locus

Lengeler, Klaus B., Cox, Gary M., Heitman, Joseph

Cryptococcus neoformans is a pathogenic basidiomycete with a defined sexual cycle involving mating between haploid yeast cells with a transient diploid state. C. neoformans occurs in four predominant...

Signal Transduction Cascades Regulating Fungal Development and Virulence

Lengeler, Klaus B., Davidson, Robert C., D'souza, Cletus, Harashima, Toshiaki, Shen, Wei-Chiang, Wang, Ping, ...

Cellular differentiation, mating, and filamentous growth are regulated in many fungi by environmental and nutritional signals. For example, in response to nitrogen limitation, diploid cells of the...

Sok2 Regulates Yeast Pseudohyphal Differentiation via a Transcription Factor Cascade That Regulates Cell-Cell Adhesion

Pan, Xuewen, Heitman, Joseph

In response to nitrogen limitation, Saccharomyces cerevisiae undergoes a dimorphic transition to filamentous pseudohyphal growth. In previous studies, the transcription factor Sok2 was found to...

Rapamycin Antifungal Action Is Mediated via Conserved Complexes with FKBP12 and TOR Kinase Homologs in Cryptococcus neoformans

Cruz, M. Cristina, Cavallo, Lora M., Görlach, Jenifer M., Cox, Gary, Perfect, John R., Cardenas, Maria E., ...

Cryptococcus neoformans is a fungal pathogen that causes meningitis in patients immunocompromised by AIDS, chemotherapy, organ transplantation, or high-dose steroids. Current antifungal drug...

Rapamycin Induces the G0 Program of Transcriptional Repression in Yeast by Interfering with the TOR Signaling Pathway

Zaragoza, Dean, Ghavidel, Ataollah, Heitman, Joseph, Schultz, Michael C.

The macrolide antibiotic rapamycin inhibits cellular proliferation by interfering with the highly conserved TOR (for target of rapamycin) signaling pathway. Growth arrest of budding yeast cells...

CNS1 Encodes an Essential p60/Sti1 Homolog in Saccharomyces cerevisiae That Suppresses Cyclophilin 40 Mutations and Interacts with Hsp90

Dolinski, Kara J., Cardenas, Maria E., Heitman, Joseph

Cyclophilins are cis-trans-peptidyl-prolyl isomerases that bind to and are inhibited by the immunosuppressant cyclosporin A (CsA). The toxic effects of CsA are mediated by the 18-kDa cyclophilin A...

Pheromones Stimulate Mating and Differentiation via Paracrine and Autocrine Signaling in Cryptococcus neoformans

Shen, Wei-Chiang, Davidson, Robert C., Cox, Gary M., Heitman, Joseph

Cryptococcus neoformans is a pathogenic fungus with a defined sexual cycle involving haploid MATα and MATa cells. Interestingly, MATα strains are more common, are more virulent than congenic MATa...

Mating-Type-Specific and Nonspecific PAK Kinases Play Shared and Divergent Roles in Cryptococcus neoformans

Wang, Ping, Nichols, Connie B., Lengeler, Klaus B., Cardenas, Maria E., Cox, Gary M., Perfect, John R., ...

Cryptococcus neoformans is an opportunistic fungal pathogen with a defined sexual cycle involving fusion of haploid MATα and MATa cells. Virulence has been linked to the mating type, and MATα cells...

Adenylyl Cyclase Functions Downstream of the Gα Protein Gpa1 and Controls Mating and Pathogenicity of Cryptococcus neoformans

Alspaugh, J. Andrew, Pukkila-Worley, Read, Harashima, Toshiaki, Cavallo, Lora M., Funnell, Deanna, Cox, Gary M., ...

The signaling molecule cyclic AMP (cAMP) is a ubiquitous second messenger that enables cells to detect and respond to extracellular signals. cAMP is generated by the enzyme adenylyl cyclase, which is...

Calcineurin is essential for survival during membrane stress in Candida albicans

Cruz, M.Cristina, Goldstein, Alan L., Blankenship, Jill R., Del Poeta, Maurizio, Davis, Dana, Cardenas, Maria E., ...

The immunosuppressants cyclosporin A (CsA) and FK506 inhibit the protein phosphatase calcineurin and block T-cell activation and transplant rejection. Calcineurin is conserved in microorganisms and...

Mating-Type Locus of Cryptococcus neoformans: a Step in the Evolution of Sex Chromosomes

Lengeler, Klaus B., Fox, Deborah S., Fraser, James A., Allen, Andria, Forrester, Keri, Dietrich, Fred S., ...

The sexual development and virulence of the fungal pathogen Cryptococcus neoformans is controlled by a bipolar mating system determined by a single locus that exists in two alleles, α and a. The α...

Protein Kinase A Operates a Molecular Switch That Governs Yeast Pseudohyphal Differentiation

Pan, Xuewen, Heitman, Joseph

The yeast Saccharomyces cerevisiae undergoes a dimorphic filamentous transition in response to nutrient cues that is affected by both mitogen-activated protein kinase and cyclic AMP-protein kinase A...

Killing of Caenorhabditis elegans by Cryptococcus neoformans as a model of yeast pathogenesis

Mylonakis, Eleftherios, Ausubel, Frederick M., Perfect, John R., Heitman, Joseph, Calderwood, Stephen B.

We found that the well-studied nematode Caenorhabditis elegans can use various yeasts, including Cryptococcus laurentii and Cryptococcus kuetzingii, as a sole source of food, producing similar brood...

Calcineurin is required for hyphal elongation during mating and haploid fruiting in Cryptococcus neoformans

Cruz, M.Cristina, Fox, Deborah S., Heitman, Joseph

Cryptococcus neoformans is a fungal pathogen that causes meningitis in immunocompromised patients. Its growth is sensitive to the immunosuppressants FK506 and cyclosporin, which inhibit the Ca2+–...

Ergosterol Biosynthesis Inhibitors Become Fungicidal when Combined with Calcineurin Inhibitors against Candida albicans, Candida glabrata, and Candida krusei

Onyewu, Chiatogu, Blankenship, Jill R., Del Poeta, Maurizio, Heitman, Joseph

Azoles target the ergosterol biosynthetic enzyme lanosterol 14α-demethylase and are a widely applied class of antifungal agents because of their broad therapeutic window, wide spectrum of activity,...

SURVEY AND SUMMARY: A nomenclature for restriction enzymes, DNA methyltransferases, homing endonucleases and their genes

Roberts, Richard J., Belfort, Marlene, Bestor, Timothy, Bhagwat, Ashok S., Bickle, Thomas A., Bitinaite, Jurate, ...

A nomenclature is described for restriction endonucleases, DNA methyltransferases, homing endonucleases and related genes and gene products. It provides explicit categories for the many different...

Calcineurin Is Essential for Candida albicans Survival in Serum and Virulence

Blankenship, Jill R., Wormley, Floyd L., Boyce, Molly K., Schell, Wiley A., Filler, Scott G., Perfect, John R., ...

Calcineurin is a calcium-activated protein phosphatase that is the target of the immunosuppressants cyclosporin A and FK506. In T cells, calcineurin controls nuclear import of the NF-AT transcription...

Disruption of Ergosterol Biosynthesis Confers Resistance to Amphotericin B in Candida lusitaniae

Young, Laura Y., Hull, Christina M., Heitman, Joseph

Candida lusitaniae is an emerging human pathogen that, unlike other fungal pathogens, frequently develops resistance to the commonly used antifungal agent amphotericin B. Amphotericin B is a member...

Physical Maps for Genome Analysis of Serotype A and D Strains of the Fungal Pathogen Cryptococcus neoformans

Schein, Jacqueline E., Tangen, Kristin L., Chiu, Readman, Shin, Heesun, Lengeler, Klaus B., MacDonald, William Kim, ...

The basidiomycete fungus Cryptococcus neoformans is an important opportunistic pathogen of humans that poses a significant threat to immunocompromised individuals. Isolates of C. neoformans are...

Sexual Cycle of Cryptococcus neoformans var. grubii and Virulence of Congenic a and α Isolates

Nielsen, Kirsten, Cox, Gary M., Wang, Ping, Toffaletti, Dena L., Perfect, John R., Heitman, Joseph

Cryptococcus neoformans is a human-pathogenic fungus that has evolved into three distinct varieties that infect most prominently the central nervous system. A sexual cycle involving haploid cells of...

Cell identity and sexual development in Cryptococcus neoformans are controlled by the mating-type-specific homeodomain protein Sxi1α

Hull, Christina M., Davidson, Robert C., Heitman, Joseph

Virulence in the human fungal pathogen Cryptococcus neoformans is associated with the α mating type. Studies to identify the properties of α cells that enhance pathogenesis have led to the...

Phospholipid-Binding Protein Cts1 Controls Septation and Functions Coordinately with Calcineurin in Cryptococcus neoformans

Fox, Deborah S., Cox, Gary M., Heitman, Joseph

Cryptococcus neoformans is an opportunistic fungal pathogen that causes life-threatening meningoencephalitis in immunocompromised patients. The Ca2+-calmodulin-activated protein phosphatase...

Recapitulation of the Sexual Cycle of the Primary Fungal Pathogen Cryptococcus neoformans var. gattii: Implications for an Outbreak on Vancouver Island, Canada†

Fraser, James A., Subaran, Ryan L., Nichols, Connie B., Heitman, Joseph

Cryptococcus neoformans is a human fungal pathogen that exists as three distinct varieties or sibling species: the predominantly opportunistic pathogens C. neoformans var. neoformans (serotype D) and...

Identification and characterization of a highly conserved calcineurin binding protein, CBP1/calcipressin, in Cryptococcus neoformans

Görlach, Jenifer, Fox, Deborah S., Cutler, N.Shane, Cox, Gary M., Perfect, John R., Heitman, Joseph

Calcineurin is the conserved target of the immunosuppressants cyclosporin A and FK506. Using the yeast two-hybrid system, we identified a novel calcineurin binding protein, CBP1, from the pathogenic...

The Ess1 prolyl isomerase is linked to chromatin remodeling complexes and the general transcription machinery

Wu, Xiaoyun, Wilcox, Cathy B., Devasahayam, Gina, Hackett, Robin L., Arévalo-Rodríguez, Miguel, Cardenas, Maria E., ...

The Ess1/Pin1 peptidyl-prolyl isomerase (PPIase) is thought to control mitosis by binding to cell cycle regulatory proteins and altering their activity. Here we isolate temperature-sensitive ess1...

Cyclophilin A and Ess1 interact with and regulate silencing by the Sin3–Rpd3 histone deacetylase

Arévalo-Rodríguez, Miguel, Cardenas, Maria E., Wu, Xiaoyun, Hanes, Steven D., Heitman, Joseph

Three families of prolyl isomerases have been identified: cyclophilins, FK506-binding proteins (FKBPs) and parvulins. All 12 cyclophilins and FKBPs are dispensable for growth in yeast, whereas the...

Cryptococcus neoformans mating and virulence are regulated by the G-protein α subunit GPA1 and cAMP

Alspaugh, J. Andrew, Perfect, John R., Heitman, Joseph

This study explores signal transduction pathways that function during mating and infection in the opportunistic, human fungal pathogen Cryptococcus neoformans. The gene encoding a G-protein α...

The TOR signaling cascade regulates gene expression in response to nutrients

Cardenas, Maria E., Cutler, N. Shane, Lorenz, Michael C., Di Como, Charles J., Heitman, Joseph

Rapamycin inhibits the TOR kinases, which regulate cell proliferation and mRNA translation and are conserved from yeast to man. The TOR kinases also regulate responses to nutrients, including...

Evidence of Sexual Recombination among Cryptococcus neoformans Serotype A Isolates in Sub-Saharan Africa†

Litvintseva, Anastasia P., Marra, Robert E., Nielsen, Kirsten, Heitman, Joseph, Vilgalys, Rytas, Mitchell, Thomas G.

The most common cause of fungal meningitis in humans, Cryptococcus neoformans serotype A, is a basidiomycetous yeast with a bipolar mating system. However, the vast majority (>99.9%) of C. neoformans...

Cyclic AMP-Dependent Protein Kinase Catalytic Subunits Have Divergent Roles in Virulence Factor Production in Two Varieties of the Fungal Pathogen Cryptococcus neoformans

Hicks, Julie K., D'Souza, Cletus A., Cox, Gary M., Heitman, Joseph

Our earlier findings established that cyclic AMP-dependent protein kinase functions in a signaling cascade that regulates mating and virulence of Cryptococcus neoformans var. grubii (serotype A)....

Challenge of Drosophila melanogaster with Cryptococcus neoformans and Role of the Innate Immune Response

Apidianakis, Yiorgos, Rahme, Laurence G., Heitman, Joseph, Ausubel, Frederick M., Calderwood, Stephen B., Mylonakis, Eleftherios

We found that the ingestion of Cryptococcus neoformans by Drosophila melanogaster resulted in the death of the fly but that the ingestion of Saccharomyces cerevisiae or the nonpathogenic Cryptococcus...

Cryptococcus neoformans Virulence Gene Discovery through Insertional Mutagenesis

Idnurm, Alexander, Reedy, Jennifer L., Nussbaum, Jesse C., Heitman, Joseph

Insertional mutagenesis was applied to Cryptococcus neoformans to identify genes associated with virulence attributes. Using biolistic transformation, we generated 4,300 nourseothricin...

In Vitro Interactions between Antifungals and Immunosuppressants against Aspergillus fumigatus

Steinbach, William J., Schell, Wiley A., Blankenship, Jill R., Onyewu, Chiatogu, Heitman, Joseph, Perfect, John R.

The optimal treatment for invasive aspergillosis remains elusive, despite the increased efficacy of newer agents. The immunosuppressants cyclosporine (CY), tacrolimus (FK506), and sirolimus (formerly...

The α-Specific Cell Identity Factor Sxi1α Is Not Required for Virulence of Cryptococcus neoformans

Hull, Christina M., Cox, Gary M., Heitman, Joseph

Cryptococcus neoformans is a human fungal pathogen that has two mating types (a and α). Experiments have shown that in some backgrounds α strains are more virulent than a strains. Our studies...

PAK Kinases Ste20 and Pak1 Govern Cell Polarity at Different Stages of Mating in Cryptococcus neoformans

Nichols, Connie B., Fraser, James A., Heitman, Joseph

Sexual identity and mating are linked to virulence of the fungal pathogen Cryptococcus neoformans. Cells of the α mating type are more prevalent and can be more virulent than a cells, and...

FKBP12 Controls Aspartate Pathway Flux in Saccharomyces cerevisiae To Prevent Toxic Intermediate Accumulation

Arévalo-Rodríguez, Miguel, Pan, Xuewen, Boeke, Jef D., Heitman, Joseph

FKBP12 is a conserved member of the prolyl-isomerase enzyme family and serves as the intracellular receptor for FK506 that mediates immunosuppression in mammals and antimicrobial actions in fungi. To...

Identification of Cryptococcus neoformans Temperature-Regulated Genes with a Genomic-DNA Microarray†

Kraus, Peter R., Boily, Marie-Josée, Giles, Steven S., Stajich, Jason E., Allen, Andria, Cox, Gary M., ...

The ability to survive and proliferate at 37°C is an essential virulence attribute of pathogenic microorganisms. A partial-genome microarray was used to profile gene expression in the...

Convergent Evolution of Chromosomal Sex-Determining Regions in the Animal and Fungal Kingdoms

Fraser, James A, Diezmann, Stephanie, Subaran, Ryan L, Allen, Andria, Lengeler, Klaus B, Dietrich, Fred S, ...

Sexual identity is governed by sex chromosomes in plants and animals, and by mating type (MAT) loci in fungi. Comparative analysis of the MAT locus from a species cluster of the human fungal pathogen...

The Calcineurin Target, Crz1, Functions in Azole Tolerance but Is Not Required for Virulence of Candida albicans

Onyewu, Chiatogu, Wormley, Floyd L., Perfect, John R., Heitman, Joseph

In Candida albicans, calcineurin is essential for virulence and survival during membrane perturbation by azoles. Crz1 is a proposed downstream target of calcineurin based on studies of Saccharomyces...

In Vitro Interactions between Antifungals and Immunosuppressants against Aspergillus fumigatus Isolates from Transplant and Nontransplant Patients

Steinbach, William J., Singh, Nina, Miller, Jackie L., Benjamin, Daniel K., Schell, Wiley A., Heitman, Joseph, ...

We performed in vitro antifungal checkerboard testing on 12 Aspergillus fumigatus clinical isolates (6 transplant recipients and 6 nontransplant patients) with three antifungal agents (amphotericin...

Adenylyl Cyclase-Associated Protein Aca1 Regulates Virulence and Differentiation of Cryptococcus neoformans via the Cyclic AMP-Protein Kinase A Cascade†

Bahn, Yong-Sun, Hicks, Julie K., Giles, Steven S., Cox, Gary M., Heitman, Joseph

The evolutionarily conserved cyclic AMP (cAMP) signaling pathway controls cell functions in response to environmental cues in organisms as diverse as yeast and mammals. In the basidiomycetous human...

Cryptococcus neoformans Isolates from Transplant Recipients Are Not Selected for Resistance to Calcineurin Inhibitors by Current Immunosuppressive Regimens

Blankenship, Jill R., Singh, Nina, Alexander, Barbara D., Heitman, Joseph

The immunosuppressants tacrolimus (FK506) and cyclosporine A inhibit calcineurin and have potent antifungal activity. In this study, 24% of Cryptococcus neoformans isolates from solid-organ...

Cyclophilin A Is Localized to the Nucleus and Controls Meiosis in Saccharomyces cerevisiae†

Arévalo-Rodríguez, Miguel, Heitman, Joseph

Cyclophilin A is conserved from yeast to humans and mediates the ability of cyclosporine to perturb signal transduction cascades via inhibition of calcineurin. Cyclophilin A also catalyzes cis-trans...

Transcriptional Network of Multiple Capsule and Melanin Genes Governed by the Cryptococcus neoformans Cyclic AMP Cascade

Pukkila-Worley, Read, Gerrald, Quincy D., Kraus, Peter R., Boily, Marie-Josée, Davis, Matthew J., Giles, Steven S., ...

Cryptococcus neoformans is an opportunistic human fungal pathogen that elaborates several virulence attributes, including a polysaccharide capsule and melanin pigments. A conserved Gα protein/cyclic...

Chromosomal Translocation and Segmental Duplication in Cryptococcus neoformans†

Fraser, James A., Huang, Johnny C., Pukkila-Worley, Read, Alspaugh, J. Andrew, Mitchell, Thomas G., Heitman, Joseph

Large chromosomal events such as translocations and segmental duplications enable rapid adaptation to new environments. Here we marshal genomic, genetic, meiotic mapping, and physical evidence to...

Light Controls Growth and Development via a Conserved Pathway in the Fungal Kingdom

Idnurm, Alexander, Heitman, Joseph

Light inhibits mating and haploid fruiting of the human fungal pathogen Cryptococcus neoformans, but the mechanisms involved were unknown. Two genes controlling light responses were discovered...

Two cyclophilin A homologs with shared and distinct functions important for growth and virulence of Cryptococcus neoformans

Wang, Ping, Cardenas, Maria E., Cox, Gary M., Perfect, John R., Heitman, Joseph

Cyclophilin A is the target of the immunosuppressant cyclosporin A (CsA) and is encoded by a single unique gene conserved from yeast to humans. In the pathogenic fungus Cryptococcus neoformans, two...

Specialization of the HOG Pathway and Its Impact on Differentiation and Virulence of Cryptococcus neoformansD⃞

Bahn, Yong-Sun, Kojima, Kaihei, Cox, Gary M., Heitman, Joseph

The human pathogenic fungus Cryptococcus neoformans has diverged from a common ancestor into three biologically distinct varieties or sibling species over the past 10–40 million years. During...

Sex-Specific Homeodomain Proteins Sxi1α and Sxi2a Coordinately Regulate Sexual Development in Cryptococcus neoformans

Hull, Christina M., Boily, Marie-Josee, Heitman, Joseph

Homeodomain proteins are central regulators of development in eukaryotes. In fungi, homeodomain proteins have been shown to control cell identity and sexual development. Cryptococcus neoformans is a...

Calcium- and Calcineurin-Independent Roles for Calmodulin in Cryptococcus neoformans Morphogenesis and High-Temperature Growth†

Kraus, Peter R., Nichols, Connie B., Heitman, Joseph

The function of calcium as a signaling molecule is conserved in eukaryotes from fungi to humans. Previous studies have identified the calcium-activated phosphatase calcineurin as a critical factor in...

The cyclophilins

Wang, Ping, Heitman, Joseph

Cyclophilins belong to a group of proteins known as immunophilins that have peptidyl-prolyl cis-trans somerase activity. Cyclophilins are found in all cells of all organisms studied. Mammalian...

Cryptococcus neoformans α Strains Preferentially Disseminate to the Central Nervous System during Coinfection

Nielsen, Kirsten, Cox, Gary M., Litvintseva, Anastasia P., Mylonakis, Eleftherios, Malliaris, Stephanie D., Benjamin, Daniel K., ...

Cryptococcus neoformans is a fungal pathogen that has evolved over the past 40 million years into three distinct varieties or sibling species (gattii, grubii, and neoformans). Each variety manifests...

Calcineurin-Binding Protein Cbp1 Directs the Specificity of Calcineurin-Dependent Hyphal Elongation during Mating in Cryptococcus neoformans

Fox, Deborah S., Heitman, Joseph

Mating and virulence of the human fungal pathogen Cryptococcus neoformans are controlled by calcineurin, a serine-threonine-specific calcium-activated phosphatase that is the target of the...

Clonality and Recombination in Genetically Differentiated Subgroups of Cryptococcus gattii†

Campbell, Leona T., Currie, Bart J., Krockenberger, Mark, Malik, Richard, Meyer, Wieland, Heitman, Joseph, ...

Cryptococcus gattii is a pathogenic yeast that together with Cryptococcus neoformans causes cryptococcosis in humans and animals. High numbers of viable C. gattii propagules can be obtained from...

Clinical and Environmental Isolates of Cryptococcus gattii from Australia That Retain Sexual Fecundity†

Campbell, Leona T., Fraser, James A., Nichols, Connie B., Dietrich, Fred S., Carter, Dee, Heitman, Joseph

Cryptococcus gattii is a primary pathogenic yeast that causes disease in both animals and humans. It is closely related to Cryptococcus neoformans and diverged from a common ancestor ∼40 million...

Cryptococcus neoformans Gene Expression during Murine Macrophage Infection†

Fan, Weihua, Kraus, Peter R., Boily, Marie-Josee, Heitman, Joseph

The fungal pathogen Cryptococcus neoformans survives phagocytosis by macrophages and proliferates within, ultimately establishing latent infection as a facultative intracellular pathogen that can...

Calcineurin Is Required for Candida albicans To Survive Calcium Stress in Serum

Blankenship, Jill R., Heitman, Joseph

The calcium-activated protein phosphatase calcineurin plays a critical role in the virulence of Candida albicans. Previous studies demonstrated that calcineurin is not required for the yeast-hypha...

Gα Subunit Gpa2 Recruits Kelch Repeat Subunits That Inhibit Receptor-G Protein Coupling during cAMP-induced Dimorphic Transitions in Saccharomyces cerevisiae

Harashima, Toshiaki, Heitman, Joseph

All eukaryotic cells sense extracellular stimuli and activate intracellular signaling cascades via G protein-coupled receptors (GPCR) and associated heterotrimeric G proteins. The Saccharomyces...

Chlamydospore Formation during Hyphal Growth in Cryptococcus neoformans

Lin, Xiaorong, Heitman, Joseph

Cryptococcus neoformans, a basidiomycetous fungal pathogen, infects hosts through inhalation and can cause fatal meningoencephalitis in individuals if untreated. This fungus undergoes a dimorphic...

Calcineurin: a central controller of signalling in eukaryotes

Aramburu, José, Heitman, Joseph, Crabtree, Gerald R.

Workshop on the Calcium/Calcineurin/NFAT Pathway: Regulation and Function

Cryptococcus neoformans Gene Involved in Mammalian Pathogenesis Identified by a Caenorhabditis elegans Progeny-Based Approach

Tang, Robin J., Breger, Julia, Idnurm, Alexander, Gerik, Kimberly J., Lodge, Jennifer K., Heitman, Joseph, ...

Caenorhabditis elegans can serve as a substitute host for the study of microbial pathogenesis. We found that mutations in genes of the fungal pathogen Cryptococcus neoformans involved in mammalian...

Pde1 Phosphodiesterase Modulates Cyclic AMP Levels through a Protein Kinase A-Mediated Negative Feedback Loop in Cryptococcus neoformans

Hicks, Julie K., Bahn, Yong-Sun, Heitman, Joseph

The virulence of the human pathogenic fungus Cryptococcus neoformans is regulated by a cyclic AMP (cAMP)-dependent protein kinase A (PKA) signaling cascade that promotes mating and the production of...

Galleria mellonella as a Model System To Study Cryptococcus neoformans Pathogenesis

Mylonakis, Eleftherios, Moreno, Roberto, El Khoury, Joseph B., Idnurm, Alexander, Heitman, Joseph, Calderwood, Stephen B., ...

Evaluation of Cryptococcus neoformans virulence in a number of nonmammalian hosts suggests that C. neoformans is a nonspecific pathogen. We used the killing of Galleria mellonella (the greater wax...

Immunotherapy with Tacrolimus (FK506) Does Not Select for Resistance to Calcineurin Inhibitors in Candida albicans Isolates from Liver Transplant Patients

Reedy, Jennifer L., Husain, Shahid, Ison, Michael, Pruett, Timothy L., Singh, Nina, Heitman, Joseph

In Candida albicans, calcineurin mediates tolerance to azole antifungal drugs, survival in serum, and virulence. In this study, we examined 24 Candida isolates from liver transplant recipients...

A Unique Fungal Two-Component System Regulates Stress Responses, Drug Sensitivity, Sexual Development, and Virulence of Cryptococcus neoformans

Bahn, Yong-Sun, Kojima, Kaihei, Cox, Gary M., Heitman, Joseph

The stress-activated mitogen-activated protein kinase (MAPK) pathway is widely used by eukaryotic organisms as a central conduit via which cellular responses to the environment effect growth and...

Interaction Between Genetic Background and the Mating-Type Locus in Cryptococcus neoformans Virulence Potential

Nielsen, Kirsten, Marra, Robert E., Hagen, Ferry, Boekhout, Teun, Mitchell, Thomas G., Cox, Gary M., ...

The study of quantitative traits provides a window on the interactions between multiple unlinked genetic loci. The interaction between hosts and pathogenic microbes, such as fungi, involves aspects...

A genetic linkage map of Cryptococcus neoformans variety neoformans serotype D (Filobasidiella neoformans).

Marra, Robert E, Huang, Johnny C, Fung, Eula, Nielsen, Kirsten, Heitman, Joseph, Vilgalys, Rytas, ...

To construct a genetic linkage map of the heterothallic yeast, Cryptococcus neoformans (Filobasidiella neoformans), we crossed two mating-compatible strains and analyzed 94 progeny for the...

The Phycomyces madA gene encodes a blue-light photoreceptor for phototropism and other light responses

Idnurm, Alexander, Rodríguez-Romero, Julio, Corrochano, Luis M., Sanz, Catalina, Iturriaga, Enrique A., Eslava, Arturo P., ...

Phycomyces blakesleeanus is a filamentous zygomycete fungus that produces striking elongated single cells that extend up to 10 cm into the air, with each such sporangiophore supporting a sphere...

Calcineurin Controls Growth, Morphology, and Pathogenicity in Aspergillus fumigatus

Steinbach, William J., Cramer, Robert A., Perfect, B. Zachary, Asfaw, Yohannes G., Sauer, Theodor C., Najvar, Laura K., ...

Calcineurin is implicated in a myriad of human diseases as well as homeostasis and virulence in several major human pathogenic microorganisms. The fungus Aspergillus fumigatus is a leading cause of...

Conserved Elements of the RAM Signaling Pathway Establish Cell Polarity in the Basidiomycete Cryptococcus neoformans in a Divergent Fashion from Other Fungi

Walton, Felicia J., Heitman, Joseph, Idnurm, Alexander

In eukaryotes the complex processes of development, differentiation, and proliferation require carefully orchestrated changes in cellular morphology. Single-celled eukaryotes provide tractable models...

Recombination Hotspots Flank the Cryptococcus Mating-Type Locus: Implications for the Evolution of a Fungal Sex Chromosome

Hsueh, Yen-Ping, Idnurm, Alexander, Heitman, Joseph

Recombination increases dramatically during meiosis to promote genetic exchange and generate recombinant progeny. Interestingly, meiotic recombination is unevenly distributed throughout genomes, and,...

Virulence Attributes and Hyphal Growth of C. neoformans Are Quantitative Traits and the MATα Allele Enhances Filamentation

Lin, Xiaorong, Huang, Johnny C, Mitchell, Thomas G, Heitman, Joseph

Cryptococcus neoformans is a fungal human pathogen with a bipolar mating system. It undergoes a dimorphic transition from a unicellular yeast to hyphal filamentous growth during mating and...

Characterization of Alcohol-induced Filamentous Growth in Saccharomyces cerevisiae

Lorenz, Michael C., Cutler, N. Shane, Heitman, Joseph

Diploid cells of the budding yeast Saccharomyces cerevisiae starved for nitrogen differentiate into a filamentous growth form. Poor carbon sources such as starches can also stimulate filamentation,...

Protection from nitrosative stress by yeast flavohemoglobin

Liu, Limin, Zeng, Ming, Hausladen, Alfred, Heitman, Joseph, Stamler, Jonathan S.

Yeast hemoglobin was discovered close to half a century ago, but its function has remained unknown. Herein, we report that this flavohemoglobin protects Saccharomyces cerevisiae from nitrosative...

Identification of the MATa mating-type locus of Cryptococcus neoformans reveals a serotype A MATa strain thought to have been extinct

Lengeler, Klaus B., Wang, Ping, Cox, Gary M., Perfect, John R., Heitman, Joseph

Cryptococcus neoformans is an opportunistic fungal pathogen with a defined sexual cycle involving mating between haploid MATa and MATα cells. Here we describe the isolation of part of the MATa...

All cyclophilins and FK506 binding proteins are, individually and collectively, dispensable for viability in Saccharomyces cerevisiae

Dolinski, Kara, Muir, Scott, Cardenas, Maria, Heitman, Joseph

The cyclophilins and FK506 binding proteins (FKBPs) bind to cyclosporin A, FK506, and rapamycin and mediate their immunosuppressive and toxic effects, but the physiological functions of these...

Protein Kinase Activity and Identification of a Toxic Effector Domain of the Target of Rapamycin TOR Proteins in Yeast

Alarcon, Clara M., Heitman, Joseph, Cardenas, Maria E.

In complex with FKBP12, the immunosuppressant rapamycin binds to and inhibits the yeast TOR1 and TOR2 proteins and the mammalian homologue mTOR/FRAP/RAFT1. The TOR proteins promote cell cycle...

Functions of FKBP12 and Mitochondrial Cyclophilin Active Site Residues In Vitro and In Vivo in Saccharomyces cerevisiae

Dolinski, Kara, Scholz, Christian, Muir, R. Scott, Rospert, Sabine, Schmid, Franz X., Cardenas, Maria E., ...

Cyclophilin and FK506 binding protein (FKBP) accelerate cis–trans peptidyl-prolyl isomerization and bind to and mediate the effects of the immunosuppressants cyclosporin A and FK506. The normal...

The TOR Signal Transduction Cascade Controls Cellular Differentiation in Response to Nutrients

Cutler, N. Shane, Pan, Xuewen, Heitman, Joseph, Cardenas, Maria E.

Rapamycin binds and inhibits the Tor protein kinases, which function in a nutrient-sensing signal transduction pathway that has been conserved from the yeast Saccharomyces cerevisiae to humans. In...

Cyclic AMP-Dependent Protein Kinase Regulates Pseudohyphal Differentiation in Saccharomyces cerevisiae

Pan, Xuewen, Heitman, Joseph

In response to nitrogen starvation, diploid cells of the yeast Saccharomyces cerevisiae differentiate to a filamentous growth form known as pseudohyphal differentiation. Filamentous growth is...

The G-Protein β Subunit GPB1 Is Required for Mating and Haploid Fruiting in Cryptococcus neoformans

Wang, Ping, Perfect, John R., Heitman, Joseph

Cryptococcus neoformans is an opportunistic fungal pathogen with a defined sexual cycle. The gene encoding a heterotrimeric G-protein β subunit, GPB1, was cloned and disrupted. gpb1 mutant strains...

Cyclic AMP-Dependent Protein Kinase Controls Virulence of the Fungal Pathogen Cryptococcus neoformans

D'Souza, Cletus A., Alspaugh, J. Andrew, Yue, Changli, Harashima, Toshiaki, Cox, Gary M., Perfect, John R., ...

Cryptococcus neoformans is an opportunistic fungal pathogen that infects the human central nervous system. This pathogen elaborates two specialized virulence factors: the antioxidant melanin and an...

Antifungal Activities of Antineoplastic Agents: Saccharomyces cerevisiae as a Model System To Study Drug Action

Cardenas, Maria E., Cruz, M. Cristina, Del Poeta, Maurizio, Chung, Namjin, Perfect, John R., Heitman, Joseph

Recent evolutionary studies reveal that microorganisms including yeasts and fungi are more closely related to mammals than was previously appreciated. Possibly as a consequence, many natural-product...

Comparison of In Vitro Activities of Camptothecin and Nitidine Derivatives against Fungal and Cancer Cells

Del Poeta, Maurizio, Chen, Shih-Fong, Von Hoff, Daniel, Dykstra, Christine C., Wani, Mansukh C., Manikumar, Govindarajan, ...

The activities of a series of camptothecin and nitidine derivatives that might interact with topoisomerase I were compared against yeast and cancer cell lines. Our findings reveal that structural...

Immunosuppressive and Nonimmunosuppressive Cyclosporine Analogs Are Toxic to the Opportunistic Fungal Pathogen Cryptococcus neoformans via Cyclophilin-Dependent Inhibition of Calcineurin

Cruz, M. Cristina, Del Poeta, Maurizio, Wang, Ping, Wenger, Roland, Zenke, Gerhard, Quesniaux, Valerie F. J., ...

Cyclosporine (CsA) is an immunosuppressive and antimicrobial drug which, in complex with cyclophilin A, inhibits the protein phosphatase calcineurin. We recently found that Cryptococcus neoformans...

Synergistic Antifungal Activities of Bafilomycin A1, Fluconazole, and the Pneumocandin MK-0991/Caspofungin Acetate (L-743,873) with Calcineurin Inhibitors FK506 and L-685,818 against Cryptococcus neoformans

Del Poeta, Maurizio, Cruz, M. Cristina, Cardenas, Maria E., Perfect, John R., Heitman, Joseph

Cryptococcus neoformans is an opportunistic fungal pathogen that causes life-threatening infections of the central nervous system. Existing therapies include amphotericin B, fluconazole, and...

Rapamycin and Less Immunosuppressive Analogs Are Toxic to Candida albicans and Cryptococcus neoformans via FKBP12-Dependent Inhibition of TOR

Cruz, M. Cristina, Goldstein, Alan L., Blankenship, Jill, Del Poeta, Maurizio, Perfect, John R., McCusker, John H., ...

Candida albicans and Cryptococcus neoformans cause both superficial and disseminated infections in humans. Current antifungal therapies for deep-seated infections are limited to amphotericin B,...

Cryptococcus neoformans Differential Gene Expression Detected In Vitro and In Vivo with Green Fluorescent Protein

Del Poeta, Maurizio, Toffaletti, Dena L., Rude, Thomas H., Sparks, Sara D., Heitman, Joseph, Perfect, John R.

Synthetic green fluorescent protein (GFP) was used as a reporter to detect differential gene expression in the pathogenic fungus Cryptococcus neoformans. Promoters from the C. neoformans actin, GAL7,...

Comparison of the Roles of Calcineurin in Physiology and Virulence in Serotype D and Serotype A Strains of Cryptococcus neoformans

Cruz, M. Cristina, Sia, Rey A. L., Olson, Michael, Cox, Gary M., Heitman, Joseph

The calcineurin gene was cloned and disrupted in serotype D strains of Cryptococcus neoformans. Serotype A and serotype D calcineurin mutants were inviable at 37°C and avirulent in mice, whereas...

Serotype AD Strains of Cryptococcus neoformans Are Diploid or Aneuploid and Are Heterozygous at the Mating-Type Locus

Lengeler, Klaus B., Cox, Gary M., Heitman, Joseph

Cryptococcus neoformans is a pathogenic basidiomycete with a defined sexual cycle involving mating between haploid yeast cells with a transient diploid state. C. neoformans occurs in four predominant...

Signal Transduction Cascades Regulating Fungal Development and Virulence

Lengeler, Klaus B., Davidson, Robert C., D'souza, Cletus, Harashima, Toshiaki, Shen, Wei-Chiang, Wang, Ping, ...

Cellular differentiation, mating, and filamentous growth are regulated in many fungi by environmental and nutritional signals. For example, in response to nitrogen limitation, diploid cells of the...

Sok2 Regulates Yeast Pseudohyphal Differentiation via a Transcription Factor Cascade That Regulates Cell-Cell Adhesion

Pan, Xuewen, Heitman, Joseph

In response to nitrogen limitation, Saccharomyces cerevisiae undergoes a dimorphic transition to filamentous pseudohyphal growth. In previous studies, the transcription factor Sok2 was found to...

Rapamycin Antifungal Action Is Mediated via Conserved Complexes with FKBP12 and TOR Kinase Homologs in Cryptococcus neoformans

Cruz, M. Cristina, Cavallo, Lora M., Görlach, Jenifer M., Cox, Gary, Perfect, John R., Cardenas, Maria E., ...

Cryptococcus neoformans is a fungal pathogen that causes meningitis in patients immunocompromised by AIDS, chemotherapy, organ transplantation, or high-dose steroids. Current antifungal drug...

Rapamycin Induces the G0 Program of Transcriptional Repression in Yeast by Interfering with the TOR Signaling Pathway

Zaragoza, Dean, Ghavidel, Ataollah, Heitman, Joseph, Schultz, Michael C.

The macrolide antibiotic rapamycin inhibits cellular proliferation by interfering with the highly conserved TOR (for target of rapamycin) signaling pathway. Growth arrest of budding yeast cells...

CNS1 Encodes an Essential p60/Sti1 Homolog in Saccharomyces cerevisiae That Suppresses Cyclophilin 40 Mutations and Interacts with Hsp90

Dolinski, Kara J., Cardenas, Maria E., Heitman, Joseph

Cyclophilins are cis-trans-peptidyl-prolyl isomerases that bind to and are inhibited by the immunosuppressant cyclosporin A (CsA). The toxic effects of CsA are mediated by the 18-kDa cyclophilin A...

Pheromones Stimulate Mating and Differentiation via Paracrine and Autocrine Signaling in Cryptococcus neoformans

Shen, Wei-Chiang, Davidson, Robert C., Cox, Gary M., Heitman, Joseph

Cryptococcus neoformans is a pathogenic fungus with a defined sexual cycle involving haploid MATα and MATa cells. Interestingly, MATα strains are more common, are more virulent than congenic MATa...

Mating-Type-Specific and Nonspecific PAK Kinases Play Shared and Divergent Roles in Cryptococcus neoformans

Wang, Ping, Nichols, Connie B., Lengeler, Klaus B., Cardenas, Maria E., Cox, Gary M., Perfect, John R., ...

Cryptococcus neoformans is an opportunistic fungal pathogen with a defined sexual cycle involving fusion of haploid MATα and MATa cells. Virulence has been linked to the mating type, and MATα cells...

Adenylyl Cyclase Functions Downstream of the Gα Protein Gpa1 and Controls Mating and Pathogenicity of Cryptococcus neoformans

Alspaugh, J. Andrew, Pukkila-Worley, Read, Harashima, Toshiaki, Cavallo, Lora M., Funnell, Deanna, Cox, Gary M., ...

The signaling molecule cyclic AMP (cAMP) is a ubiquitous second messenger that enables cells to detect and respond to extracellular signals. cAMP is generated by the enzyme adenylyl cyclase, which is...

Calcineurin is essential for survival during membrane stress in Candida albicans

Cruz, M.Cristina, Goldstein, Alan L., Blankenship, Jill R., Del Poeta, Maurizio, Davis, Dana, Cardenas, Maria E., ...

The immunosuppressants cyclosporin A (CsA) and FK506 inhibit the protein phosphatase calcineurin and block T-cell activation and transplant rejection. Calcineurin is conserved in microorganisms and...

Mating-Type Locus of Cryptococcus neoformans: a Step in the Evolution of Sex Chromosomes

Lengeler, Klaus B., Fox, Deborah S., Fraser, James A., Allen, Andria, Forrester, Keri, Dietrich, Fred S., ...

The sexual development and virulence of the fungal pathogen Cryptococcus neoformans is controlled by a bipolar mating system determined by a single locus that exists in two alleles, α and a. The α...

Protein Kinase A Operates a Molecular Switch That Governs Yeast Pseudohyphal Differentiation

Pan, Xuewen, Heitman, Joseph

The yeast Saccharomyces cerevisiae undergoes a dimorphic filamentous transition in response to nutrient cues that is affected by both mitogen-activated protein kinase and cyclic AMP-protein kinase A...

Killing of Caenorhabditis elegans by Cryptococcus neoformans as a model of yeast pathogenesis

Mylonakis, Eleftherios, Ausubel, Frederick M., Perfect, John R., Heitman, Joseph, Calderwood, Stephen B.

We found that the well-studied nematode Caenorhabditis elegans can use various yeasts, including Cryptococcus laurentii and Cryptococcus kuetzingii, as a sole source of food, producing similar brood...

Calcineurin is required for hyphal elongation during mating and haploid fruiting in Cryptococcus neoformans

Cruz, M.Cristina, Fox, Deborah S., Heitman, Joseph

Cryptococcus neoformans is a fungal pathogen that causes meningitis in immunocompromised patients. Its growth is sensitive to the immunosuppressants FK506 and cyclosporin, which inhibit the Ca2+–...

Ergosterol Biosynthesis Inhibitors Become Fungicidal when Combined with Calcineurin Inhibitors against Candida albicans, Candida glabrata, and Candida krusei

Onyewu, Chiatogu, Blankenship, Jill R., Del Poeta, Maurizio, Heitman, Joseph

Azoles target the ergosterol biosynthetic enzyme lanosterol 14α-demethylase and are a widely applied class of antifungal agents because of their broad therapeutic window, wide spectrum of activity,...

SURVEY AND SUMMARY: A nomenclature for restriction enzymes, DNA methyltransferases, homing endonucleases and their genes

Roberts, Richard J., Belfort, Marlene, Bestor, Timothy, Bhagwat, Ashok S., Bickle, Thomas A., Bitinaite, Jurate, ...

A nomenclature is described for restriction endonucleases, DNA methyltransferases, homing endonucleases and related genes and gene products. It provides explicit categories for the many different...

Calcineurin Is Essential for Candida albicans Survival in Serum and Virulence

Blankenship, Jill R., Wormley, Floyd L., Boyce, Molly K., Schell, Wiley A., Filler, Scott G., Perfect, John R., ...

Calcineurin is a calcium-activated protein phosphatase that is the target of the immunosuppressants cyclosporin A and FK506. In T cells, calcineurin controls nuclear import of the NF-AT transcription...

Disruption of Ergosterol Biosynthesis Confers Resistance to Amphotericin B in Candida lusitaniae

Young, Laura Y., Hull, Christina M., Heitman, Joseph

Candida lusitaniae is an emerging human pathogen that, unlike other fungal pathogens, frequently develops resistance to the commonly used antifungal agent amphotericin B. Amphotericin B is a member...

Physical Maps for Genome Analysis of Serotype A and D Strains of the Fungal Pathogen Cryptococcus neoformans

Schein, Jacqueline E., Tangen, Kristin L., Chiu, Readman, Shin, Heesun, Lengeler, Klaus B., MacDonald, William Kim, ...

The basidiomycete fungus Cryptococcus neoformans is an important opportunistic pathogen of humans that poses a significant threat to immunocompromised individuals. Isolates of C. neoformans are...

Sexual Cycle of Cryptococcus neoformans var. grubii and Virulence of Congenic a and α Isolates

Nielsen, Kirsten, Cox, Gary M., Wang, Ping, Toffaletti, Dena L., Perfect, John R., Heitman, Joseph

Cryptococcus neoformans is a human-pathogenic fungus that has evolved into three distinct varieties that infect most prominently the central nervous system. A sexual cycle involving haploid cells of...

Cell identity and sexual development in Cryptococcus neoformans are controlled by the mating-type-specific homeodomain protein Sxi1α

Hull, Christina M., Davidson, Robert C., Heitman, Joseph

Virulence in the human fungal pathogen Cryptococcus neoformans is associated with the α mating type. Studies to identify the properties of α cells that enhance pathogenesis have led to the...

Phospholipid-Binding Protein Cts1 Controls Septation and Functions Coordinately with Calcineurin in Cryptococcus neoformans

Fox, Deborah S., Cox, Gary M., Heitman, Joseph

Cryptococcus neoformans is an opportunistic fungal pathogen that causes life-threatening meningoencephalitis in immunocompromised patients. The Ca2+-calmodulin-activated protein phosphatase...

Recapitulation of the Sexual Cycle of the Primary Fungal Pathogen Cryptococcus neoformans var. gattii: Implications for an Outbreak on Vancouver Island, Canada†

Fraser, James A., Subaran, Ryan L., Nichols, Connie B., Heitman, Joseph

Cryptococcus neoformans is a human fungal pathogen that exists as three distinct varieties or sibling species: the predominantly opportunistic pathogens C. neoformans var. neoformans (serotype D) and...

Identification and characterization of a highly conserved calcineurin binding protein, CBP1/calcipressin, in Cryptococcus neoformans

Görlach, Jenifer, Fox, Deborah S., Cutler, N.Shane, Cox, Gary M., Perfect, John R., Heitman, Joseph

Calcineurin is the conserved target of the immunosuppressants cyclosporin A and FK506. Using the yeast two-hybrid system, we identified a novel calcineurin binding protein, CBP1, from the pathogenic...

The Ess1 prolyl isomerase is linked to chromatin remodeling complexes and the general transcription machinery

Wu, Xiaoyun, Wilcox, Cathy B., Devasahayam, Gina, Hackett, Robin L., Arévalo-Rodríguez, Miguel, Cardenas, Maria E., ...

The Ess1/Pin1 peptidyl-prolyl isomerase (PPIase) is thought to control mitosis by binding to cell cycle regulatory proteins and altering their activity. Here we isolate temperature-sensitive ess1...

Cyclophilin A and Ess1 interact with and regulate silencing by the Sin3–Rpd3 histone deacetylase

Arévalo-Rodríguez, Miguel, Cardenas, Maria E., Wu, Xiaoyun, Hanes, Steven D., Heitman, Joseph

Three families of prolyl isomerases have been identified: cyclophilins, FK506-binding proteins (FKBPs) and parvulins. All 12 cyclophilins and FKBPs are dispensable for growth in yeast, whereas the...

Cryptococcus neoformans mating and virulence are regulated by the G-protein α subunit GPA1 and cAMP

Alspaugh, J. Andrew, Perfect, John R., Heitman, Joseph

This study explores signal transduction pathways that function during mating and infection in the opportunistic, human fungal pathogen Cryptococcus neoformans. The gene encoding a G-protein α...

The TOR signaling cascade regulates gene expression in response to nutrients

Cardenas, Maria E., Cutler, N. Shane, Lorenz, Michael C., Di Como, Charles J., Heitman, Joseph

Rapamycin inhibits the TOR kinases, which regulate cell proliferation and mRNA translation and are conserved from yeast to man. The TOR kinases also regulate responses to nutrients, including...

Evidence of Sexual Recombination among Cryptococcus neoformans Serotype A Isolates in Sub-Saharan Africa†

Litvintseva, Anastasia P., Marra, Robert E., Nielsen, Kirsten, Heitman, Joseph, Vilgalys, Rytas, Mitchell, Thomas G.

The most common cause of fungal meningitis in humans, Cryptococcus neoformans serotype A, is a basidiomycetous yeast with a bipolar mating system. However, the vast majority (>99.9%) of C. neoformans...

Cyclic AMP-Dependent Protein Kinase Catalytic Subunits Have Divergent Roles in Virulence Factor Production in Two Varieties of the Fungal Pathogen Cryptococcus neoformans

Hicks, Julie K., D'Souza, Cletus A., Cox, Gary M., Heitman, Joseph

Our earlier findings established that cyclic AMP-dependent protein kinase functions in a signaling cascade that regulates mating and virulence of Cryptococcus neoformans var. grubii (serotype A)....

Challenge of Drosophila melanogaster with Cryptococcus neoformans and Role of the Innate Immune Response

Apidianakis, Yiorgos, Rahme, Laurence G., Heitman, Joseph, Ausubel, Frederick M., Calderwood, Stephen B., Mylonakis, Eleftherios

We found that the ingestion of Cryptococcus neoformans by Drosophila melanogaster resulted in the death of the fly but that the ingestion of Saccharomyces cerevisiae or the nonpathogenic Cryptococcus...

Cryptococcus neoformans Virulence Gene Discovery through Insertional Mutagenesis

Idnurm, Alexander, Reedy, Jennifer L., Nussbaum, Jesse C., Heitman, Joseph

Insertional mutagenesis was applied to Cryptococcus neoformans to identify genes associated with virulence attributes. Using biolistic transformation, we generated 4,300 nourseothricin...

In Vitro Interactions between Antifungals and Immunosuppressants against Aspergillus fumigatus

Steinbach, William J., Schell, Wiley A., Blankenship, Jill R., Onyewu, Chiatogu, Heitman, Joseph, Perfect, John R.

The optimal treatment for invasive aspergillosis remains elusive, despite the increased efficacy of newer agents. The immunosuppressants cyclosporine (CY), tacrolimus (FK506), and sirolimus (formerly...

The α-Specific Cell Identity Factor Sxi1α Is Not Required for Virulence of Cryptococcus neoformans

Hull, Christina M., Cox, Gary M., Heitman, Joseph

Cryptococcus neoformans is a human fungal pathogen that has two mating types (a and α). Experiments have shown that in some backgrounds α strains are more virulent than a strains. Our studies...

PAK Kinases Ste20 and Pak1 Govern Cell Polarity at Different Stages of Mating in Cryptococcus neoformans

Nichols, Connie B., Fraser, James A., Heitman, Joseph

Sexual identity and mating are linked to virulence of the fungal pathogen Cryptococcus neoformans. Cells of the α mating type are more prevalent and can be more virulent than a cells, and...

FKBP12 Controls Aspartate Pathway Flux in Saccharomyces cerevisiae To Prevent Toxic Intermediate Accumulation

Arévalo-Rodríguez, Miguel, Pan, Xuewen, Boeke, Jef D., Heitman, Joseph

FKBP12 is a conserved member of the prolyl-isomerase enzyme family and serves as the intracellular receptor for FK506 that mediates immunosuppression in mammals and antimicrobial actions in fungi. To...

Identification of Cryptococcus neoformans Temperature-Regulated Genes with a Genomic-DNA Microarray†

Kraus, Peter R., Boily, Marie-Josée, Giles, Steven S., Stajich, Jason E., Allen, Andria, Cox, Gary M., ...

The ability to survive and proliferate at 37°C is an essential virulence attribute of pathogenic microorganisms. A partial-genome microarray was used to profile gene expression in the...

Convergent Evolution of Chromosomal Sex-Determining Regions in the Animal and Fungal Kingdoms

Fraser, James A, Diezmann, Stephanie, Subaran, Ryan L, Allen, Andria, Lengeler, Klaus B, Dietrich, Fred S, ...

Sexual identity is governed by sex chromosomes in plants and animals, and by mating type (MAT) loci in fungi. Comparative analysis of the MAT locus from a species cluster of the human fungal pathogen...

The Calcineurin Target, Crz1, Functions in Azole Tolerance but Is Not Required for Virulence of Candida albicans

Onyewu, Chiatogu, Wormley, Floyd L., Perfect, John R., Heitman, Joseph

In Candida albicans, calcineurin is essential for virulence and survival during membrane perturbation by azoles. Crz1 is a proposed downstream target of calcineurin based on studies of Saccharomyces...

In Vitro Interactions between Antifungals and Immunosuppressants against Aspergillus fumigatus Isolates from Transplant and Nontransplant Patients

Steinbach, William J., Singh, Nina, Miller, Jackie L., Benjamin, Daniel K., Schell, Wiley A., Heitman, Joseph, ...

We performed in vitro antifungal checkerboard testing on 12 Aspergillus fumigatus clinical isolates (6 transplant recipients and 6 nontransplant patients) with three antifungal agents (amphotericin...

Adenylyl Cyclase-Associated Protein Aca1 Regulates Virulence and Differentiation of Cryptococcus neoformans via the Cyclic AMP-Protein Kinase A Cascade†

Bahn, Yong-Sun, Hicks, Julie K., Giles, Steven S., Cox, Gary M., Heitman, Joseph

The evolutionarily conserved cyclic AMP (cAMP) signaling pathway controls cell functions in response to environmental cues in organisms as diverse as yeast and mammals. In the basidiomycetous human...

Cryptococcus neoformans Isolates from Transplant Recipients Are Not Selected for Resistance to Calcineurin Inhibitors by Current Immunosuppressive Regimens

Blankenship, Jill R., Singh, Nina, Alexander, Barbara D., Heitman, Joseph

The immunosuppressants tacrolimus (FK506) and cyclosporine A inhibit calcineurin and have potent antifungal activity. In this study, 24% of Cryptococcus neoformans isolates from solid-organ...

Cyclophilin A Is Localized to the Nucleus and Controls Meiosis in Saccharomyces cerevisiae†

Arévalo-Rodríguez, Miguel, Heitman, Joseph

Cyclophilin A is conserved from yeast to humans and mediates the ability of cyclosporine to perturb signal transduction cascades via inhibition of calcineurin. Cyclophilin A also catalyzes cis-trans...

Transcriptional Network of Multiple Capsule and Melanin Genes Governed by the Cryptococcus neoformans Cyclic AMP Cascade

Pukkila-Worley, Read, Gerrald, Quincy D., Kraus, Peter R., Boily, Marie-Josée, Davis, Matthew J., Giles, Steven S., ...

Cryptococcus neoformans is an opportunistic human fungal pathogen that elaborates several virulence attributes, including a polysaccharide capsule and melanin pigments. A conserved Gα protein/cyclic...

Chromosomal Translocation and Segmental Duplication in Cryptococcus neoformans†

Fraser, James A., Huang, Johnny C., Pukkila-Worley, Read, Alspaugh, J. Andrew, Mitchell, Thomas G., Heitman, Joseph

Large chromosomal events such as translocations and segmental duplications enable rapid adaptation to new environments. Here we marshal genomic, genetic, meiotic mapping, and physical evidence to...

Light Controls Growth and Development via a Conserved Pathway in the Fungal Kingdom

Idnurm, Alexander, Heitman, Joseph

Light inhibits mating and haploid fruiting of the human fungal pathogen Cryptococcus neoformans, but the mechanisms involved were unknown. Two genes controlling light responses were discovered...

Two cyclophilin A homologs with shared and distinct functions important for growth and virulence of Cryptococcus neoformans

Wang, Ping, Cardenas, Maria E., Cox, Gary M., Perfect, John R., Heitman, Joseph

Cyclophilin A is the target of the immunosuppressant cyclosporin A (CsA) and is encoded by a single unique gene conserved from yeast to humans. In the pathogenic fungus Cryptococcus neoformans, two...

Specialization of the HOG Pathway and Its Impact on Differentiation and Virulence of Cryptococcus neoformansD⃞

Bahn, Yong-Sun, Kojima, Kaihei, Cox, Gary M., Heitman, Joseph

The human pathogenic fungus Cryptococcus neoformans has diverged from a common ancestor into three biologically distinct varieties or sibling species over the past 10–40 million years. During...

Sex-Specific Homeodomain Proteins Sxi1α and Sxi2a Coordinately Regulate Sexual Development in Cryptococcus neoformans

Hull, Christina M., Boily, Marie-Josee, Heitman, Joseph

Homeodomain proteins are central regulators of development in eukaryotes. In fungi, homeodomain proteins have been shown to control cell identity and sexual development. Cryptococcus neoformans is a...

Calcium- and Calcineurin-Independent Roles for Calmodulin in Cryptococcus neoformans Morphogenesis and High-Temperature Growth†

Kraus, Peter R., Nichols, Connie B., Heitman, Joseph

The function of calcium as a signaling molecule is conserved in eukaryotes from fungi to humans. Previous studies have identified the calcium-activated phosphatase calcineurin as a critical factor in...

Galleria mellonella as a Model System To Study Cryptococcus neoformans Pathogenesis

Mylonakis, Eleftherios, Moreno, Roberto, El Khoury, Joseph B., Idnurm, Alexander, Heitman, Joseph, Calderwood, Stephen B., ...

Evaluation of Cryptococcus neoformans virulence in a number of nonmammalian hosts suggests that C. neoformans is a nonspecific pathogen. We used the killing of Galleria mellonella (the greater wax...

The cyclophilins

Wang, Ping, Heitman, Joseph

Cyclophilins belong to a group of proteins known as immunophilins that have peptidyl-prolyl cis-trans somerase activity. Cyclophilins are found in all cells of all organisms studied. Mammalian...

Cryptococcus neoformans α Strains Preferentially Disseminate to the Central Nervous System during Coinfection

Nielsen, Kirsten, Cox, Gary M., Litvintseva, Anastasia P., Mylonakis, Eleftherios, Malliaris, Stephanie D., Benjamin, Daniel K., ...

Cryptococcus neoformans is a fungal pathogen that has evolved over the past 40 million years into three distinct varieties or sibling species (gattii, grubii, and neoformans). Each variety manifests...

Calcineurin-Binding Protein Cbp1 Directs the Specificity of Calcineurin-Dependent Hyphal Elongation during Mating in Cryptococcus neoformans

Fox, Deborah S., Heitman, Joseph

Mating and virulence of the human fungal pathogen Cryptococcus neoformans are controlled by calcineurin, a serine-threonine-specific calcium-activated phosphatase that is the target of the...

Clonality and Recombination in Genetically Differentiated Subgroups of Cryptococcus gattii†

Campbell, Leona T., Currie, Bart J., Krockenberger, Mark, Malik, Richard, Meyer, Wieland, Heitman, Joseph, ...

Cryptococcus gattii is a pathogenic yeast that together with Cryptococcus neoformans causes cryptococcosis in humans and animals. High numbers of viable C. gattii propagules can be obtained from...

Clinical and Environmental Isolates of Cryptococcus gattii from Australia That Retain Sexual Fecundity†

Campbell, Leona T., Fraser, James A., Nichols, Connie B., Dietrich, Fred S., Carter, Dee, Heitman, Joseph

Cryptococcus gattii is a primary pathogenic yeast that causes disease in both animals and humans. It is closely related to Cryptococcus neoformans and diverged from a common ancestor ∼40 million...

Cryptococcus neoformans Gene Expression during Murine Macrophage Infection†

Fan, Weihua, Kraus, Peter R., Boily, Marie-Josee, Heitman, Joseph

The fungal pathogen Cryptococcus neoformans survives phagocytosis by macrophages and proliferates within, ultimately establishing latent infection as a facultative intracellular pathogen that can...

Calcineurin Is Required for Candida albicans To Survive Calcium Stress in Serum

Blankenship, Jill R., Heitman, Joseph

The calcium-activated protein phosphatase calcineurin plays a critical role in the virulence of Candida albicans. Previous studies demonstrated that calcineurin is not required for the yeast-hypha...

Gα Subunit Gpa2 Recruits Kelch Repeat Subunits That Inhibit Receptor-G Protein Coupling during cAMP-induced Dimorphic Transitions in Saccharomyces cerevisiae

Harashima, Toshiaki, Heitman, Joseph

All eukaryotic cells sense extracellular stimuli and activate intracellular signaling cascades via G protein-coupled receptors (GPCR) and associated heterotrimeric G proteins. The Saccharomyces...

Chlamydospore Formation during Hyphal Growth in Cryptococcus neoformans

Lin, Xiaorong, Heitman, Joseph

Cryptococcus neoformans, a basidiomycetous fungal pathogen, infects hosts through inhalation and can cause fatal meningoencephalitis in individuals if untreated. This fungus undergoes a dimorphic...

Calcineurin: a central controller of signalling in eukaryotes

Aramburu, José, Heitman, Joseph, Crabtree, Gerald R.

Workshop on the Calcium/Calcineurin/NFAT Pathway: Regulation and Function

Cryptococcus neoformans Gene Involved in Mammalian Pathogenesis Identified by a Caenorhabditis elegans Progeny-Based Approach

Tang, Robin J., Breger, Julia, Idnurm, Alexander, Gerik, Kimberly J., Lodge, Jennifer K., Heitman, Joseph, ...

Caenorhabditis elegans can serve as a substitute host for the study of microbial pathogenesis. We found that mutations in genes of the fungal pathogen Cryptococcus neoformans involved in mammalian...

Pde1 Phosphodiesterase Modulates Cyclic AMP Levels through a Protein Kinase A-Mediated Negative Feedback Loop in Cryptococcus neoformans

Hicks, Julie K., Bahn, Yong-Sun, Heitman, Joseph

The virulence of the human pathogenic fungus Cryptococcus neoformans is regulated by a cyclic AMP (cAMP)-dependent protein kinase A (PKA) signaling cascade that promotes mating and the production of...

G Protein-coupled Receptor Gpr4 Senses Amino Acids and Activates the cAMP-PKA Pathway in Cryptococcus neoformansD⃞

Xue, Chaoyang, Bahn, Yong-Sun, Cox, Gary M., Heitman, Joseph

The Gα protein Gpa1 governs the cAMP-PKA signaling pathway and plays a central role in virulence and differentiation in the human fungal pathogen Cryptococcus neoformans, but the signals and...

Immunotherapy with Tacrolimus (FK506) Does Not Select for Resistance to Calcineurin Inhibitors in Candida albicans Isolates from Liver Transplant Patients

Reedy, Jennifer L., Husain, Shahid, Ison, Michael, Pruett, Timothy L., Singh, Nina, Heitman, Joseph

In Candida albicans, calcineurin mediates tolerance to azole antifungal drugs, survival in serum, and virulence. In this study, we examined 24 Candida isolates from liver transplant recipients...

The Phycomyces madA gene encodes a blue-light photoreceptor for phototropism and other light responses

Idnurm, Alexander, Rodríguez-Romero, Julio, Corrochano, Luis M., Sanz, Catalina, Iturriaga, Enrique A., Eslava, Arturo P., ...

Phycomyces blakesleeanus is a filamentous zygomycete fungus that produces striking elongated single cells that extend up to 10 cm into the air, with each such sporangiophore supporting a sphere...

Interaction Between Genetic Background and the Mating-Type Locus in Cryptococcus neoformans Virulence Potential

Nielsen, Kirsten, Marra, Robert E., Hagen, Ferry, Boekhout, Teun, Mitchell, Thomas G., Cox, Gary M., ...

The study of quantitative traits provides a window on the interactions between multiple unlinked genetic loci. The interaction between hosts and pathogenic microbes, such as fungi, involves aspects...

A genetic linkage map of Cryptococcus neoformans variety neoformans serotype D (Filobasidiella neoformans).

Marra, Robert E, Huang, Johnny C, Fung, Eula, Nielsen, Kirsten, Heitman, Joseph, Vilgalys, Rytas, ...

To construct a genetic linkage map of the heterothallic yeast, Cryptococcus neoformans (Filobasidiella neoformans), we crossed two mating-compatible strains and analyzed 94 progeny for the...

A Unique Fungal Two-Component System Regulates Stress Responses, Drug Sensitivity, Sexual Development, and Virulence of Cryptococcus neoformans

Bahn, Yong-Sun, Kojima, Kaihei, Cox, Gary M., Heitman, Joseph

The stress-activated mitogen-activated protein kinase (MAPK) pathway is widely used by eukaryotic organisms as a central conduit via which cellular responses to the environment effect growth and...

Calcineurin Controls Growth, Morphology, and Pathogenicity in Aspergillus fumigatus

Steinbach, William J., Cramer, Robert A., Perfect, B. Zachary, Asfaw, Yohannes G., Sauer, Theodor C., Najvar, Laura K., ...

Calcineurin is implicated in a myriad of human diseases as well as homeostasis and virulence in several major human pathogenic microorganisms. The fungus Aspergillus fumigatus is a leading cause of...

Conserved Elements of the RAM Signaling Pathway Establish Cell Polarity in the Basidiomycete Cryptococcus neoformans in a Divergent Fashion from Other Fungi

Walton, Felicia J., Heitman, Joseph, Idnurm, Alexander

In eukaryotes the complex processes of development, differentiation, and proliferation require carefully orchestrated changes in cellular morphology. Single-celled eukaryotes provide tractable models...

Recombination Hotspots Flank the Cryptococcus Mating-Type Locus: Implications for the Evolution of a Fungal Sex Chromosome

Hsueh, Yen-Ping, Idnurm, Alexander, Heitman, Joseph

Recombination increases dramatically during meiosis to promote genetic exchange and generate recombinant progeny. Interestingly, meiotic recombination is unevenly distributed throughout genomes, and,...

Virulence Attributes and Hyphal Growth of C. neoformans Are Quantitative Traits and the MATα Allele Enhances Filamentation

Lin, Xiaorong, Huang, Johnny C, Mitchell, Thomas G, Heitman, Joseph

Cryptococcus neoformans is a fungal human pathogen with a bipolar mating system. It undergoes a dimorphic transition from a unicellular yeast to hyphal filamentous growth during mating and...

Calcineurin Promotes Infection of the Cornea by Candida albicans and Can Be Targeted To Enhance Fluconazole Therapy▿

Onyewu, Chiatogu, Afshari, Natalie A., Heitman, Joseph

In an established Candida albicans murine keratitis model, combination therapy with ophthalmic preparations of fluconazole and cyclosporine A (CsA) demonstrated in vivo drug synergy and effectively...

Peroxisome Function Regulates Growth on Glucose in the Basidiomycete Fungus Cryptococcus neoformans▿

Idnurm, Alexander, Giles, Steven S., Perfect, John R., Heitman, Joseph

The function of the peroxisomes was examined in the pathogenic basidiomycete Cryptococcus neoformans. Recent studies reveal the glyoxylate pathway is required for virulence of diverse microbial...

Divergence of Protein Kinase A Catalytic Subunits in Cryptococcus neoformans and Cryptococcus gattii Illustrates Evolutionary Reconfiguration of a Signaling Cascade▿ †

Hicks, Julie K., Heitman, Joseph

Gene duplication and divergence via both the loss and gain of gene activities are powerful evolutionary forces underlying the origin of new biological functions. Here a comparative genetics approach...

Evolution of the Mating Type Locus: Insights Gained from the Dimorphic Primary Fungal Pathogens Histoplasma capsulatum, Coccidioides immitis, and Coccidioides posadasii▿ †

Fraser, James A., Stajich, Jason E., Tarcha, Eric J., Cole, Garry T., Inglis, Diane O., Sil, Anita, ...

Sexual reproduction of fungi is governed by the mating type (MAT) locus, a specialized region of the genome encoding key transcriptional regulators that direct regulatory networks to specify cell...

Many Globally Isolated AD Hybrid Strains of Cryptococcus neoformans Originated in Africa

Litvintseva, Anastasia P, Lin, Xiaorong, Templeton, Irka, Heitman, Joseph, Mitchell, Thomas G

Interspecific and intervarietal hybridization may contribute to the biological diversity of fungal populations. Cryptococcus neoformans is a pathogenic yeast and the most common fungal cause of...

Cryptococcus neoformans Mates on Pigeon Guano: Implications for the Realized Ecological Niche and Globalization▿

Nielsen, Kirsten, De Obaldia, Anna L., Heitman, Joseph

The ecological niche that a species can occupy is determined by its resource requirements and the physical conditions necessary for survival. The niche to which an organism is most highly adapted is...

G protein signaling governing cell fate decisions involves opposing Gα subunits in Cryptococcus neoformans

Hsueh, Yen-Ping, Xue, Chaoyang, Heitman, Joseph

Communication between cells and their environments is often mediated by G protein-coupled receptors and cognate G proteins. In fungi, one such signaling cascade is the mating pathway triggered by...

αADα Hybrids of Cryptococcus neoformans: Evidence of Same-Sex Mating in Nature and Hybrid Fitness

Lin, Xiaorong, Litvintseva, Anastasia P, Nielsen, Kirsten, Patel, Sweta, Floyd, Anna, Mitchell, Thomas G, ...

Cryptococcus neoformans is a ubiquitous human fungal pathogen that causes meningoencephalitis in predominantly immunocompromised hosts. The fungus is typically haploid, and sexual reproduction...

Eca1, a Sarcoplasmic/Endoplasmic Reticulum Ca2+-ATPase, Is Involved in Stress Tolerance and Virulence in Cryptococcus neoformans▿

Fan, Weihua, Idnurm, Alexander, Breger, Julia, Mylonakis, Eleftherios, Heitman, Joseph

The basidiomycetous fungal pathogen Cryptococcus neoformans is adapted to survive challenges in the soil and environment and within the unique setting of the mammalian host. A C. neoformans mutant...

Calcineurin Inhibition or Mutation Enhances Cell Wall Inhibitors against Aspergillus fumigatus▿

Steinbach, William J., Cramer, Robert A., Perfect, B. Zachary, Henn, Christina, Nielsen, Kirsten, Heitman, Joseph, ...

Calcineurin mutation or inhibition enhanced the antifungal morphological effect of cell wall inhibitors caspofungin or nikkomycin Z against Aspergillus fumigatus. Quantification of 1,3-β-d-glucan...

Targeting the Calcineurin Pathway Enhances Ergosterol Biosynthesis Inhibitors against Trichophyton mentagrophytes In Vitro and in a Human Skin Infection Model▿

Onyewu, Chiatogu, Eads, Emily, Schell, Wiley A., Perfect, John R., Ullmann, Yehuda, Kaufman, Gil, ...

Fluconazole-FK506 or fluconazole-cyclosporine drug combinations were tested in an ex vivo Trichophyton mentagrophytes human skin infection model. Conidia colonization was monitored by scanning...

First Contemporary Case of Human Infection with Cryptococcus gattii in Puget Sound: Evidence for Spread of the Vancouver Island Outbreak▿

Upton, Arlo, Fraser, James A., Kidd, Sarah E., Bretz, Camille, Bartlett, Karen H., Heitman, Joseph, ...

We report a case of cryptococcosis due to C. gattii which appears to have been acquired in the Puget Sound region, Washington State. Genotyping confirmed identity to the predominant Vancouver Island...

Ssk2 Mitogen-Activated Protein Kinase Kinase Kinase Governs Divergent Patterns of the Stress-Activated Hog1 Signaling Pathway in Cryptococcus neoformans▿ †

Bahn, Yong-Sun, Geunes-Boyer, Scarlett, Heitman, Joseph

The stress-activated p38/Hog1 mitogen-activated protein kinase (MAPK) pathway is structurally conserved in many diverse organisms, including fungi and mammals, and modulates myriad cellular...

Impact of Ammonium Permeases MepA, MepB, and MepC on Nitrogen-Regulated Secondary Metabolism in Fusarium fujikuroi▿

Teichert, Sabine, Rutherford, Julian C., Wottawa, Marieke, Heitman, Joseph, Tudzynski, Bettina

In Fusarium fujikuroi, the production of gibberellins and bikaverin is repressed by nitrogen sources such as glutamine or ammonium. Sensing and uptake of ammonium by specific permeases play key roles...

Amt2 Permease Is Required To Induce Ammonium-Responsive Invasive Growth and Mating in Cryptococcus neoformans▿

Rutherford, Julian C., Lin, Xiaorong, Nielsen, Kirsten, Heitman, Joseph

The conserved AmtB/Mep/Rh family of proteins mediate the transport of ammonium across cellular membranes in a wide range of organisms. Certain fungal members of this group are required to initiate...

Synergistic Effect of Calcineurin Inhibitors and Fluconazole against Candida albicans Biofilms▿

Uppuluri, Priya, Nett, Jeniel, Heitman, Joseph, Andes, David

Calcineurin is a Ca2+-calmodulin-activated serine/threonine-specific protein phosphatase that governs multiple aspects of fungal physiology, including cation homeostasis, morphogenesis, antifungal...

A Mep2-dependent Transcriptional Profile Links Permease Function to Gene Expression during Pseudohyphal Growth in Saccharomyces cerevisiae

Rutherford, Julian C., Chua, Gordon, Hughes, Timothy, Cardenas, Maria E., Heitman, Joseph

The ammonium permease Mep2 is required for the induction of pseudohyphal growth, a process in Saccharomyces cerevisiae that occurs in response to nutrient limitation. Mep2 has both a transport and a...

Calcineurin Target CrzA Regulates Conidial Germination, Hyphal Growth, and Pathogenesis of Aspergillus fumigatus▿ †

Cramer, Robert A., Perfect, B. Zachary, Pinchai, Nadthanan, Park, Steven, Perlin, David S., Asfaw, Yohannes G., ...

The calcineurin pathway is a critical signal transduction pathway in fungi that mediates growth, morphology, stress responses, and pathogenicity. The importance of the calcineurin pathway in fungal...

Impact of Mating Type, Serotype, and Ploidy on the Virulence of Cryptococcus neoformans▿ †

Lin, Xiaorong, Nielsen, Kirsten, Patel, Sweta, Heitman, Joseph

Hybridization with polyploidization is a significant biological force driving evolution. The effect of combining two distinct genomes in one organism on the virulence potential of pathogenic fungi is...

Diploids in the Cryptococcus neoformans Serotype A Population Homozygous for the α Mating Type Originate via Unisexual Mating

Lin, Xiaorong, Patel, Sweta, Litvintseva, Anastasia P., Floyd, Anna, Mitchell, Thomas G., Heitman, Joseph

The ubiquitous environmental human pathogen Cryptococcus neoformans is traditionally considered a haploid fungus with a bipolar mating system. In nature, the α mating type is overwhelmingly...

The Protein Kinase Tor1 Regulates Adhesin Gene Expression in Candida albicans

Bastidas, Robert J., Heitman, Joseph, Cardenas, Maria E.

Eukaryotic cell growth is coordinated in response to nutrient availability, growth factors, and environmental stimuli, enabling cell–cell interactions that promote survival. The rapamycin-sensitive...

Calcineurin Localizes to the Hyphal Septum in Aspergillus fumigatus: Implications for Septum Formation and Conidiophore Development▿ †

Juvvadi, Praveen Rao, Fortwendel, Jarrod R., Pinchai, Nadthanan, Perfect, B. Zachary, Heitman, Joseph, Steinbach, William J.

A functional calcineurin A fusion to enhanced green fluorescent protein (EGFP), CnaA-EGFP, was expressed in the Aspergillus fumigatus ΔcnaA mutant. CnaA-EGFP localized in actively growing hyphal...

Transitions in Sexuality: Recapitulation of an Ancestral Tri- and Tetrapolar Mating System in Cryptococcus neoformans▿ †

Hsueh, Yen-Ping, Fraser, James A., Heitman, Joseph

Sex is orchestrated by the mating-type locus (MAT) in fungi and by sex chromosomes in plants and animals. In fungi, two patterns of sexuality occur: bipolar with a single, typically biallelic sex...

Isolates of Cryptococcus neoformans from Infected Animals Reveal Genetic Exchange in Unisexual, α Mating Type Populations▿ †

Bui, Tien, Lin, Xiaorong, Malik, Richard, Heitman, Joseph, Carter, Dee

Sexual reproduction and genetic exchange are important for the evolution of fungal pathogens and for producing potentially infective spores. Studies to determine whether sex occurs in the pathogenic...

First Reported Case of Cryptococcus gattii in the Southeastern USA: Implications for Travel-Associated Acquisition of an Emerging Pathogen

Byrnes, Edmond J., Li, Wenjun, Lewit, Yonathan, Perfect, John R., Carter, Dee A., Cox, Gary M., ...

In 2007, the first confirmed case of Cryptococcus gattii was reported in the state of North Carolina, USA. An otherwise healthy HIV negative male patient presented with a large upper thigh...

Loss of Allergen 1 Confers a Hypervirulent Phenotype That Resembles Mucoid Switch Variants of Cryptococcus neoformans▿ †

Jain, Neena, Li, Li, Hsueh, Ye-Ping, Guerrero, Abraham, Heitman, Joseph, Goldman, David L., ...

Microbial survival in a host is usually dependent on the ability of a pathogen to undergo changes that promote escape from host defense mechanisms. The human-pathogenic fungus Cryptococcus neoformans...

Phylogeny and Phenotypic Characterization of Pathogenic Cryptococcus Species and Closely Related Saprobic Taxa in the Tremellales ▿ †

Findley, Keisha, Rodriguez-Carres, Marianela, Metin, Banu, Kroiss, Johannes, Fonseca, Álvaro, Vilgalys, Rytas, ...

The basidiomycetous yeasts Cryptococcus neoformans and Cryptococcus gattii are closely related sibling species that cause respiratory and neurological disease in humans and animals. Within these two...

Identification of ENA1 as a Virulence Gene of the Human Pathogenic Fungus Cryptococcus neoformans through Signature-Tagged Insertional Mutagenesis ▿

Idnurm, Alexander, Walton, Felicia J., Floyd, Anna, Reedy, Jennifer L., Heitman, Joseph

A library of more than 4,500 signature-tagged insertion mutants of the human pathogenic fungus Cryptococcus neoformans was generated, and a subset was screened in a murine inhalation model to...

Aspergillus fumigatus Calcipressin CbpA Is Involved in Hyphal Growth and Calcium Homeostasis▿ †

Pinchai, Nadthanan, Perfect, B. Zachary, Juvvadi, Praveen Rao, Fortwendel, Jarrod R., Cramer, Robert A., Asfaw, Yohannes G., ...

Calcineurin is a conserved protein phosphatase that plays a critical role in Ca2+ signaling and stress responses. Previously, a new class of conserved calcineurin-binding proteins, the calcipressins,...

Phycomyces MADB interacts with MADA to form the primary photoreceptor complex for fungal phototropism

Sanz, Catalina, Rodríguez-Romero, Julio, Idnurm, Alexander, Christie, John M., Heitman, Joseph, Corrochano, Luis M., ...

The fungus Phycomyces blakesleeanus reacts to environmental signals, including light, gravity, touch, and the presence of nearby objects, by changing the speed and direction of growth of its fruiting...

Generation of genetic diversity in microsporidia via sexual reproduction and horizontal gene transfer

Lee, Soo Chan, Weiss, Louis M, Heitman, Joseph

Microsporidia are obligate intracellular pathogens mainly infecting both vertebrate and invertebrate hosts. The group comprises approximately 150 genera with 1,200 species. Due to sequence divergence...