George B. Witman

Differential Expression of the C s and C�1 Isoforms of the Catalytic Subunit of Cyclic 3�,5�-Adenosine Monophosphate-Dependent Protein Kinase (2008)

In Testicular Cells, George B. Witman

The amino terminus of the sperm cAMP-dependent protein kinase catalytic subunit (termed C s) differs from that of the C�1 isoform expressed in most tissues due to the use of alternative transcripts...

Mutations in Hydin impair ciliary motility in mice (2008)

Lechtreck, Karl-Ferdinand, Delmotte, Philippe, Robinson, Michael L., Sanderson, Michael J., Witman, George B.

Chlamydomonas reinhardtii hydin is a central pair protein required for flagellar motility, and mice with Hydin defects develop lethal hydrocephalus. To determine if defects in Hydin cause...

Function and dynamics of PKD2 in Chlamydomonas reinhardtii flagella (2007)

Huang, Kaiyao, Diener, Dennis R., Mitchell, Aaron, Pazour, Gregory J., Witman, George B., Rosenbaum, Joel L.

To analyze the function of ciliary polycystic kidney disease 2 (PKD2) and its relationship to intraflagellar transport (IFT), we cloned the gene encoding Chlamydomonas reinhardtii PKD2 (CrPKD2), a...

The Chlamydomonas genome reveals the evolution of key animal and plant functions (2007)

Merchant, Sabeeha S., Prochnik, Simon E., Witman, George B., Pazour, Gregory J., Rokhsar, Daniel S., Grossman, Arthur R.

Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as...

The Chlamydomonas Genome Reveals the Evolution of Key Animal and Plant Functions (2007)

Merchant, Sabeeha S., Prochnik, Simon E., Vallon, Olivier, Harris, Elizabeth H., Karpowicz, Steven J., Witman, George B., ...

Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as...

The Chlamydomonas Genome Reveals the Evolution of Key Animal and Plant Functions (2007)

Merchant, Sabeeha S., Prochnik, Simon E., Vallon, Olivier, Harris, Elizabeth H., Karpowicz, Steven J., Witman, George B., ...

Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as...

Functional analysis of an individual IFT protein: IFT46 is required for transport of outer dynein arms into flagella (2007)

Hou, Yuqing, Qin, Hongmin, Follit, John A., Pazour, Gregory J., Rosenbaum, Joel L., Witman, George B.

Intraflagellar transport (IFT), which is the bidirectional movement of particles within flagella, is required for flagellar assembly. IFT particles are composed of approximately 16 proteins, which...

Functional analysis of an individual IFT protein: IFT46 is required for transport of outer dynein arms into flagella (2007)

Hou, Yuqing, Qin, Hongmin, Follit, John A., Pazour, Gregory J., Rosenbaum, Joel L., Witman, George B.

Intraflagellar transport (IFT), which is the bidirectional movement of particles within flagella, is required for flagellar assembly. IFT particles are composed of approximately 16 proteins, which...

Chlamydomonas reinhardtii hydin is a central pair protein required for flagellar motility (2007)

Lechtreck, Karl-Ferdinand, Witman, George B.

Mutations in Hydin cause hydrocephalus in mice, and HYDIN is a strong candidate for causing hydrocephalus in humans. The gene is conserved in ciliated species, including Chlamydomonas reinhardtii. An...

The Chlamydomonas genome reveals the evolution of key animal and plant functions. (2007)

Merchant, Sabeeha S., Prochnik, Simon E., Vallon, Olivier, Harris, Elizabeth H., Karpowicz, Steven J., Witman, George B., ...

Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as...

Radial spoke proteins of Chlamydomonas flagella (2006)

Yang, Pinfen, Diener, Dennis R., Yang, Chun, Kohno, Takahiro, Pazour, Gregory J., Dienes, Jennifer M., ...

The radial spoke is a ubiquitous component of '9+2' cilia and flagella, and plays an essential role in the control of dynein arm activity by relaying signals from the central pair of microtubules to...

Cytoplasmic dynein nomenclature (2005)

Pfister, K. Kevin, Fisher, Elizabeth M. C., Gibbons, Ian R., Hays, Thomas S., Holzbaur, Erika L. F., McIntosh, J. Richard, ...

A variety of names has been used in the literature for the subunits of cytoplasmic dynein complexes. Thus, there is a strong need for a more definitive consensus statement on nomenclature. This is...

Differential light chain assembly influences outer arm dynein motor function (2005)

DiBella, Linda M., Gorbatyuk, Oksana, Sakato, Miho, Wakabayashi, Ken-ichi, Patel-King, Ramila S., Pazour, Gregory J., ...

Tctex1 and Tctex2 were originally described as potential distorters/sterility factors in the non-Mendelian transmission of t-haplotypes in mice. These proteins have since been identified as subunits...

Proteomic analysis of a eukaryotic cilium (2005)

Pazour, Gregory J., Agrin, Nathan S., Leszyk, John D., Witman, George B.

Cilia and flagella are widespread cell organelles that have been highly conserved throughout evolution and play important roles in motility, sensory perception, and the life cycles of eukaryotes...

Identification of predicted human outer dynein arm genes: candidates for primary ciliary dyskinesia genes (2005)

Pazour, Gregory J., Agrin, Nathan S., Walker, Bethany L., Witman, George B.

BACKGROUND: Primary ciliary dyskinesia (PCD) is a severe inherited disorder characterised by chronic respiratory disease, male infertility, and, in approximately 50% of affected individuals, a...

Novel role for a sterol response element binding protein in directing spermatogenic cell-specific gene expression (2004)

Wang, Hong, San Agustin, Jovenal T., Witman, George B., Kilpatrick, Daniel L.

Sperm are highly specialized cells, and their formation requires the synthesis of a large number of unique mRNAs. However, little is known about the transcriptional mechanisms that direct male germ...

Pericentrin forms a complex with intraflagellar transport proteins and polycystin-2 and is required for primary cilia assembly (2004)

Jurczyk, Agata, Gromley, Adam Scott, Redick, Sambra D., San Agustin, Jovenal T., Witman, George B., Pazour, Gregory J., ...

Primary cilia are nonmotile microtubule structures that assemble from basal bodies by a process called intraflagellar transport (IFT) and are associated with several human diseases. Here, we show...

A dynein light intermediate chain, D1bLIC, is required for retrograde intraflagellar transport (2004)

Hou, Yuqing, Pazour, Gregory J., Witman, George B.

Intraflagellar transport (IFT), the bidirectional movement of particles along flagella, is essential for flagellar assembly. The motor for retrograde IFT in Chlamydomonas is cytoplasmic dynein 1b,...

Oda5p, a novel axonemal protein required for assembly of the outer dynein arm and an associated adenylate kinase (2004)

Wirschell, Maureen, Pazour, Gregory J., Yoda, Akinori, Hirono, Masafumi, Kamiya, Ritsu, Witman, George B.

Of the uncloned ODA genes required for outer dynein arm assembly in Chlamydomonas, ODA5 and ODA10 are of particular interest because they do not encode known subunits of the outer arm or the outer...

The autosomal recessive polycystic kidney disease protein is localized to primary cilia, with concentration in the basal body area (2004)

Wang, Shixuan, Luo, Ying, Wilson, Patricia D., Witman, George B., Zhou, Jing

Recent evidence suggests that structural and functional abnormalities of primary cilia in kidney epithelia are associated with mouse and human autosomal dominant polycystic kidney disease. To...

Cell motility: deaf Drosophila keep the beat (2003)

Witman, George B.

Intraflagellar transport is involved in the assembly of cilia and eukaryotic flagella. Two recent studies have shown that defects in intraflagellar transport prevent assembly of sensory cilia in...

DC3, the 21-kDa subunit of the outer dynein arm-docking complex (ODA-DC), is a novel EF-hand protein important for assembly of both the outer arm and the ODA-DC (2003)

Casey, Diane M., Inaba, Kazuo, Pazour, Gregory J., Takada, Saeko, Wakabayashi, Ken-ichi, Wilkerson, Curtis G., ...

The outer dynein arm-docking complex (ODA-DC) is a microtubule-associated structure that targets the outer dynein arm to its binding site on the flagellar axoneme (Takada et al. 2002. Mol. Biol. Cell...

DC3, the smallest subunit of the Chlamydomonas flagellar outer dynein arm-docking complex, is a redox-sensitive calcium-binding protein (2003)

Casey, Diane M., Yagi, Toshiki, Kamiya, Ritsu, Witman, George B.

The outer dynein arm-docking complex (ODA-DC) targets the outer dynein arm to its correct binding site on the flagellar axoneme. The Chlamydomonas ODA-DC contains three proteins; loss of any one...

The vertebrate primary cilium is a sensory organelle (2003)

Pazour, Gregory J., Witman, George B.

The primary cilium is a generally non-motile cilium that occurs singly on most cells in the vertebrate body. The function of this organelle, which has been the subject of much speculation but little...

Intraflagellar transport (2002)

Rosenbaum, Joel L., Witman, George B.

Eukaryotic cilia and flagella, including primary cilia and sensory cilia, are highly conserved organelles that project from the surfaces of many cells. The assembly and maintenance of these nearly...

The intraflagellar transport protein, IFT88, is essential for vertebrate photoreceptor assembly and maintenance (2002)

Pazour, Gregory J., Baker, Sheila A., Deane, James A., Cole, Douglas G., Dickert, Bethany L., Rosenbaum, Joel L., ...

Approximately 10% of the photoreceptor outer segment (OS) is turned over each day, requiring large amounts of lipid and protein to be moved from the inner segment to the OS. Defects in...

The outer dynein arm-docking complex: composition and characterization of a subunit (oda1) necessary for outer arm assembly (2002)

Takada, Saeko, Wilkerson, Curtis G., Wakabayashi, Ken-ichi, Kamiya, Ritsu, Witman, George B.

To learn more about how dyneins are targeted to specific sites in the flagellum, we have investigated a factor necessary for binding of outer arm dynein to the axonemal microtubules of Chlamydomonas....

Differential expression of the C(s) and Calpha1 isoforms of the catalytic subunit of cyclic 3',5'-adenosine monophosphate-dependent protein kinase testicular cells (2001)

San Agustin, Jovenal T., Witman, George B.

The amino terminus of the sperm cAMP-dependent protein kinase catalytic subunit (termed C(s)) differs from that of the Calpha1 isoform expressed in most tissues due to the use of alternative...

Transport and arrangement of the outer-dynein-arm docking complex in the flagella of Chlamydomonas mutants that lack outer dynein arms (2001)

Wakabayashi, Ken-ichi, Takada, Saeko, Witman, George B., Kamiya, Ritsu

The outer dynein arms of Chlamydomonas flagella are attached to a precise site on the outer doublet microtubules and repeat at a regular interval of 24 nm. This binding is mediated by the outer...

Forward and reverse genetic analysis of microtubule motors in Chlamydomonas (2001)

Pazour, Gregory J., Witman, George B.

The ability to integrate biochemical, cell biological, and genetic approaches makes Chlamydomonas reinhardtii the premier model organism for studies of the eukaryotic flagellum and its associated...

Chlamydomonas IFT88 and its mouse homologue, polycystic kidney disease gene tg737, are required for assembly of cilia and flagella (2000)

Pazour, Gregory J., Dickert, Bethany L., Vucica, Yvonne, Seeley, E. Scott, Rosenbaum, Joel L., Witman, George B., ...

Intraflagellar transport (IFT) is a rapid movement of multi-subunit protein particles along flagellar microtubules and is required for assembly and maintenance of eukaryotic flagella. We cloned and...

The unique catalytic subunit of sperm cAMP-dependent protein kinase is the product of an alternative Calpha mRNA expressed specifically in spermatogenic cells (2000)

San Agustin, Jovenal T., Wilkerson, Curtis G., Witman, George B.

cAMP-dependent protein kinase has a central role in the control of mammalian sperm capacitation and motility. Previous protein biochemical studies indicated that the only cAMP-dependent protein...

LC2, the chlamydomonas homologue of the t complex-encoded protein Tctex2, is essential for outer dynein arm assembly (1999)

Pazour, Gregory J., Koutoulis, Anthony, Benashski, Sharon E., Dickert, Bethany L., Sheng, Hong, Patel-King, Ramila S., ...

Tctex2 is thought to be one of the distorter genes of the mouse t haplotype. This complex greatly biases the segregation of the chromosome that carries it such that in heterozygous +/t males, the t...

An insertional mutant of Chlamydomonas reinhardtii with defective microtubule positioning (1999)

Horst, Cynthia J., Fishkind, Douglas J., Pazour, Gregory J., Witman, George B.

cmu1-1 is a new mutation of Chlamydomonas reinhardtii that causes a change in cell shape due to an alteration of cytoplasmic microtubule organization. cmu1 mutant cells were first identified based on...

The DHC1b (DHC2) isoform of cytoplasmic dynein is required for flagellar assembly (1999)

Pazour, Gregory J., Dickert, Bethany L., Witman, George B.

Dyneins are microtubule-based molecular motors involved in many different types of cell movement. Most dynein heavy chains (DHCs) clearly group into cytoplasmic or axonemal isoforms. However, DHC1b...

The catalytic subunit of the cAMP-dependent protein kinase of ovine sperm flagella has a unique amino-terminal sequence (1998)

San Agustin, Jovenal T., Leszyk, John D., Nuwaysir, Lydia M., Witman, George B.

The basis for the unusual properties of the catalytic subunit (C) of ram sperm cAMP-dependent protein kinase was investigated. Ram sperm C was purified and found by mass spectrometry (MS) to be...

A dynein light chain is essential for the retrograde particle movement of intraflagellar transport (IFT) (1998)

Pazour, Gregory J., Wilkerson, Curtis G., Witman, George B.

Several enzymes, including cytoplasmic and flagellar outer arm dynein, share an Mr 8,000 light chain termed LC8. The function of this chain is unknown, but it is highly conserved between a wide...

The Chlamydomonas reinhardtii ODA3 gene encodes a protein of the outer dynein arm docking complex (1997)

Koutoulis, Anthony, Pazour, Gregory J., Wilkerson, Curtis G., Inaba, Kazuo, Sheng, Hong, Takada, Saeko, ...

We have used an insertional mutagenesis/ gene tagging technique to generate new Chlamydomonas reinhardtii mutants that are defective in assembly of the uter ynein rm. Among 39 insertional oda mutants...

Functional interaction between Chlamydomonas outer arm dynein subunits: the gamma subunit suppresses the ATPase activity of the alpha beta dimer (1997)

Nakamura, Ken-ichi, Wilkerson, Curtis G., Witman, George B.

The alpha beta dimer and the gamma subunit of the Chlamydomonas outer arm dynein were solubilized by treating isolated axonemes with 0.6 M KCI, and purified by sucrose density gradient...

The 78,000-M(r) intermediate chain of Chlamydomonas outer arm dynein is a microtubule-binding protein (1995)

King, Stephen M., Patel-King, Ramila S., Wilkerson, Curtis G., Witman, George B.

A previous study (King et al., 1991. J. Biol. Chem. 266:8401-8407) showed that the 78,000-M(r) intermediate chain (IC78) from the Chlamydomonas outer arm dynein is in direct contact with...

Mutational analysis of the phototransduction pathway of Chlamydomonas reinhardtii (1995)

Pazour, Gregory J., Sineshchekov, Oleg A., Witman, George B.

Chlamydomonas has two photobehavioral responses, phototaxis and photoshock. Rhodopsin is the photoreceptor for these responses and the signal transduction process involves transmembrane Ca2+ fluxes....

Interspecies conservation of outer arm dynein intermediate chain sequences defines two intermediate chain subclasses (1995)

Ogawa, Kazuo, Kamiya, Ritsu, Wilkerson, Curtis G., Witman, George B.

Immunological analysis showed that antibodies against the intermediate chains (ICs) IC2 and IC3 of sea urchin outer arm dynein specifically cross-reacted with intermediate chains IC78 and IC69,...

The 78,000 M(r) intermediate chain of Chlamydomonas outer arm dynein isa WD-repeat protein required for arm assembly (1995)

Wilkerson, Curtis G., King, Stephen M., Koutoulis, Anthony, Pazour, Gregory J., Witman, George B.

We have isolated and sequenced a full-length cDNA clone encoding the 78,000 Mr intermediate chain (IC78) of the Chlamydomonas outer arm dynein. This protein previously was shown to be located at the...

Electron micrographic studies of transport of oligodeoxynucleotides across eukaryotic cell membranes (1994)

Zamecnik, Paul, Aghajanian, John, Zamecnik, Mary, Goodchild, John, Witman, George B.

Unmodified oligodeoxynucleotides (ODNs) were synthesized and tested for their ability to cross external eukaryotic cell membranes and to enter the cytosol and nucleus in tissue cultures. The ODNs...

Molecular analysis of the gamma heavy chain of Chlamydomonas flagellar outer-arm dynein (1994)

Wilkerson, Curtis G., King, Stephen M., Witman, George B.

We report here the complete sequence of the gamma dynein heavy chain of the outer arm of the Chlamydomonas flagellum, and partial sequences for six other dynein heavy chains. The gamma dynein heavy...

Multiple sites of phosphorylation within the alpha heavy chain of Chlamydomonas outer arm dynein (1994)

King, Stephen M., Witman, George B.

We have examined the phosphorylation of the alpha dynein heavy chain (DHC) from the outer arm of the Chlamydomonas flagellum. Quantitative analysis indicates that this DHC is phosphorylated at a...

Role of cAMP in the reactivation of demembranated ram spermatozoa (1994)

San Agustin, Jovenal T., Witman, George B.

Ejaculated ram sperm were demembranated with Triton X-100, separated from the detergent-soluble matrix, and reactivated [San Agustin and Witman (1993): Cell Motil. Cytoskeleton 24:264-273]. The...

Novel touch-induced, Ca(2+)-dependent phobic response in a flagellate green alga (1994)

Kreimer, Georg, Witman, George B.

The biflagellate green alga Spermatozopsis similis exhibits a remarkable avoidance reaction in addition to the photophobic or stop response characteristic of such algae. S. similis normally swims...

Chlamydomonas phototaxis (1993)

Witman, George B.

Chlamydomonas has long been a favourite organism for genetic and biochemical studies of flagellar motility and assembly, photosynthesis, and organelle genomes. With the recent development of...

A Chlamydomonas outer arm dynein mutant with a truncated beta heavy chain (1993)

Sakakibara, Hitoshi, Takada, Saeko, King, Stephen M., Witman, George B., Kamiya, Ritsu

A new allele of the Chlamydomonas oda4 flagellar mutant (oda4-s7) possessing abnormal outer dynein arms was isolated. Unlike the previously described oda4 axoneme lacking all three (alpha, beta, and...

ptx1, a nonphototactic mutant of Chlamydomonas, lacks control of flagellar dominance (1993)

Horst, Cynthia J., Witman, George B.

A new mutant strain of Chlamydomonas, ptx1, has been identified which is defective in phototaxis. This strain swims with a rate and straightness of path comparable with that of wild-type cells, and...

Reactivation of demembranated, cytosol-free ram spermatozoa (1993)

San Agustin, Jovenal T., Witman, George B.

A procedure for preparing cytosol-free ram sperm models was developed. Sperm are introduced to a Triton X-100-containing demembranation medium layered on top of a discontinuous Percoll gradient....

The motile beta/IC1 subunit of sea urchin sperm outer arm dynein does not form a rigor bond (1992)

Moss, Anthony G., Gatti, Jean-Luc, Witman, George B.

We used in vitro translocation and cosedimentation assays to study the microtubule binding properties of sea urchin sperm outer arm dynein and its beta/IC1 subunit. Microtubules glided on...

The alpha subunit of sea urchin sperm outer arm dynein mediates structural and rigor binding to microtubules (1992)

Moss, Anthony G., Sale, Winfield S., Fox, Laura A., Witman, George B.

Glass-adsorbed intact sea urchin outer arm dynein and its beta/IC1 subunit supports movement of microtubules, yet does not form a rigor complex upon depletion of ATP (16). We show here that rigor is...

Axonemal dyneins (1992)

Witman, George B.

Recent advances in our understanding of the axonemal dyneins reveal them to be much more complex than previously believed. A combination of genetic, molecular genetic, ultrastructural and biochemical...

The Mr 78,000 intermediate chain of Chlamydomonas outer arm dynein interacts with alpha-tubulin in situ (1991)

King, Stephen M., Wilkerson, Curtis G., Witman, George B.

We have used the zero-length cross-linker 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) to examine protein-protein associations within purified outer arm dynein and axonemes from Chlamydomonas...

Localization of an intermediate chain of outer arm dynein by immunoelectron microscopy (1990)

King, Stephen M., Witman, George B.

We have used immunoelectron microscopy to determine the location of an intermediate chain in the isolated outer arm dynein from Chlamydomonas flagella. When the purified alpha beta dimer of the outer...

Outer-arm dynein from trout spermatozoa: substructural organization (1990)

King, Stephen M., Gatti, Jean-Luc, Moss, Anthony G., Witman, George B.

Outer-arm dynein purified from trout spermatozoa was disrupted by low-ionic-strength dialysis, and the resulting subunits were separated by sucrose density-gradient centrifugation. The intact 19 S...

Outer arm dynein from trout spermatozoa. Purification, polypeptide composition, and enzymatic properties (1989)

Gatti, Jean-Luc, King, Stephen M., Moss, Anthony G., Witman, George B.

Extraction of isolated axonemes from trout (Salmo gairdneri) sperm with 0.6 M NaCl removed 97% of the outer arms, approximately 12% of the protein, and approximately 50% of the MgATPase activity....

Structure of the alpha and beta heavy chains of the outer arm dynein from Chlamydomonas flagella. Nucleotide binding sites (1989)

King, Stephen M., Haley, Boyd E., Witman, George B.

The photoaffinity analogs 2-azidoadenosine 5'-tri(di)-phosphate (2-N3AT(D)P) and 8-azidoadenosine 5'-triphosphate (8-N3ATP) have been used to probe the substructural organization of the nucleotide...

Structure of the gamma heavy chain of the outer arm dynein from Chlamydomonas flagella (1988)

King, Stephen M., Witman, George B.

We describe here the vanadate-dependent photocleavage of the gamma heavy chain from the Chlamydomonas outer arm dynein and the pathways by which this molecule is degraded by endoproteases. UV...

Structure of the alpha and beta heavy chains of the outer arm dynein from Chlamydomonas flagella. Location of epitopes and protease-sensitive sites (1988)

King, Stephen M., Witman, George B.

We describe here the pathways by which the alpha and beta heavy chains of the outer arm dynein from Chlamydomonas flagella are degraded by endoproteases. By probing the digestion products with...

Structure of the alpha and beta heavy chains of the outer arm dynein from Chlamydomonas flagella. Masses of chains and sites of ultraviolet-induced vanadate-dependent cleavage (1987)

King, Stephen M., Witman, George B.

We report here on the UV-induced vanadate-dependent cleavage of the alpha and beta heavy chains of the outer arm dynein from Chlamydomonas flagella. Both polypeptides are cleaved at a single site...

Isolated flagellar outer arm dynein translocates brain microtubules in vitro (1987)

Paschal, Bryce Mark, King, Stephen M., Moss, Anthony G., Collins, Christine A., Vallee, Richard B., Witman, George B.

The inner and outer arms of the flagellar axoneme generate the forces needed for flagellar movement; these arms contain ATPases called dyneins. To date, there has been no method for studying the...

A two-step procedure for efficient electrotransfer of both high-molecular-weight (greater than 400,000) and low-molecular-weight (less than 20,000) proteins (1987)

Otter, Tim, King, Stephen M., Witman, George B.

We have developed conditions for the efficient electrotransfer from polyacrylamide gels to nitrocellulose sheets of a broad size range of proteins (Mr 8,000 to Mr greater than 400,000). The important...

Flagellar movement of intact and demembranated, reactivated ram spermatozoa (1987)

Ishijima, Sumio, Witman, George B.

The flagellar movement of intact ejaculated ram sperm, and of demembranated models reactivated with ATP, has been studied using high-speed, high-resolution video microscopy. Intact sperm attached to...

Labeling of Chlamydomonas 18 S dynein polypeptides by 8-azidoadenosine 5'-triphosphate, a photoaffinity analog of ATP (1985)

Pfister, K. Kevin, Haley, Boyd E., Witman, George B.

The 18 S dynein from the outer arm of Chlamydomonas flagella is composed of an alpha subunit containing an alpha heavy chain (Mr = approximately 340,000) and an Mr = 16,000 light chain, and a beta...

Characterization of monoclonal antibodies against Chlamydomonas flagellar dyneins by high-resolution protein blotting (1985)

King, Stephen M., Otter, Tim, Witman, George B.

Monoclonal antibodies that recognize individual polypeptides of the outer arm dyneins of Chlamydomonas flagella were obtained and used to study the structural relationships between the various...

Basal bodies and associated structures are not required for normal flagellar motion or phototaxis in the green alga Chlorogonium elongatum (1985)

Hoops, Harold J., Witman, George B.

The interphase flagellar apparatus of the green alga Chlorogonium elongatum resembles that of Chlamydomonas reinhardtii in the possession of microtubular rootlets and striated fibers. However,...

Subfractionation of Chlamydomonas 18 S dynein into two unique subunits containing ATPase activity (1984)

Pfister, K. Kevin, Witman, George B.

The 18 S dynein of the outer arm of Chlamydomonas flagella contains two different heavy polypeptide chains (Mr approximately equal to 340,000), two intermediate chains (Mr = 69,000 and 78,000), and...

The photoaffinity probe 8-azidoadenosine 5'-triphosphate selectively labels the heavy chain of Chlamydomonas 12 S dynein (1984)

Pfister, K. Kevin, Haley, Boyd E., Witman, George B.

Chlamydomonas 12 S dynein, which makes up part of the outer arm of the flagellar axoneme, consists of three polypeptides of 330,000, 22,000, and 18,000 daltons. We have used 8-azidoadenosine...

Flagellar waveform and rotational orientation in a Chlamydomonas mutant lacking normal striated fibers (1984)

Hoops, Harold J., Wright, Robin L., Jarvik, Jonathan W., Witman, George B.

The Chlamydomonas mutant vfl-3 lacks normal striated fibers and microtubular rootlets. Although the flagella beat vigorously, the cells rarely display effective forward swimming. High speed...

Submicromolar levels of calcium control the balance of beating between the two flagella in demembranated models of Chlamydomonas (1984)

Kamiya, Ritsu, Witman, George B.

When detergent-extracted, demembranated cell models of Chlamydomonas were resuspended in reactivation solutions containing less than 10(-8) M Ca++, many models initially swam in helical paths similar...

Outer doublet heterogeneity reveals structural polarity related to beat direction in Chlamydomonas flagella (1983)

Hoops, Harold J., Witman, George B.

Analysis of serial cross-sections of the Chlamydomonas flagellum reveals several structural asymmetries in the axoneme. One doublet lacks the outer dynein arm, has a beak-like projection in its...

Synthesis, transport, and utilization of specific flagellar proteins during flagellar regeneration in Chlamydomonas (1982)

Remillard, Stephen P., Witman, George B.

We labeled gametes of Chlamydomonas with 10-min pulses of 35SO4(-2) before and at various times after deflagellation, and isolated whole cells and flagella immediately after the pulse. The labeled...

Dynein arm conformation and mechanochemical transduction in the eukaryotic flagellum (1982)

Witman, George B., Minervini, N.

When partially disrupted axonemes of Chlamydomonas were negatively stained in the presence of ATP, the dynein arms appeared club-shaped and were tilted proximally. In the absence of ATP, or in the...

Purification and polypeptide composition of dynein ATPases from Chlamydomonas flagella (1982)

Pfister, K. Kevin, Fay, Rose B., Witman, George B.

Extraction of isolated, demembranated flagellar axonemes of Chlamydomonas reinhardii with 0.6 M KCl solubilized 77-92% of the total axonemal Mg++ or Ca++-ATPase activity, which sedimented as 18S and...

Functionally significant central-pair rotation in a primitive eukaryotic flagellum (1981)

Omoto, Charlotte K., Witman, George B.

There is now considerable evidence that the basis for ciliary and flagellar movement is an active sliding between peripheral doublet microtubules which, when resisted by structures within the...

Purification of calmodulin from Chlamydomonas: calmodulin occurs in cell bodies and flagella (1980)

Gitelman, Stephen E., Witman, George B.

Calmodulin has been purified from cell bodies of the green alga Chlamydomonas by Ca++-dependent affinity chromatography on fluphenazine-Sepharose 4B. Calmodulin from this primitive organism closely...

Effects of adenylyl imidodiphosphate, a nonhydrolyzable adenosine triphosphate analog, on reactivated and rigor wave sea urchin sperm (1978)

Penningroth, Stephen M., Witman, George B.

A nonhydrolyzable ATP analog, adenylyl imidodiphosphate (AMP-PNP), has been used to study the role of ATP binding in flagellar motility. Sea urchin sperm of Lytechinus pictus were demembranated,...

Chlamydomonas flagellar mutants lacking radial spokes and central tubules. Structure, composition, and function of specific axonemal components (1978)

Witman, George B., Plummer, J., Sander, Greta

The fine structure, protein composition, and roles in flagellar movement of specific axonemal components were studied in wild-type Chlamydomonas and paralyzed mutants pf-14, pf-15A, and pf-19....

Tubulin requires tau for growth onto microtubule initiating sites (1976)

Witman, George B., Cleveland, Don W., Weingarten, Murray D., Kirschner, Marc W.

Tubulin purified by phosphocellulose chromatography and free of accessory proteins will not form microtubules in the absence or presence of microtubule initiating sites (flagellar microtubules). The...

Directionality of brain microtubule assembly in vitro (1974)

Dentler, William L., Granett, Sandra, Witman, George B., Rosenbaum, Joel L.

Chicks were injected intra-cerebrally with [(3)H]leucine, and (3)H-labeled microtubules were assembled in vitro in the brain supernatants. Pieces of these (3)H-labeled microtubules were then...

Comparison of the microtubule proteins of neuroblastoma cells, brain, and Chlamydomonas flagella (1971)

Olmsted, Joanna B., Witman, George B., Carlson, K., Rosenbaum, Joel L.

Intact A microtubules isolated from outer doublet microtubules of Chlamydomonas flagella contain two separable proteins (tubulins) that differ in molecular weight and in amino-acid composition. The...

The Unique Catalytic Subunit of Sperm cAMP-dependent Protein Kinase Is the Product of an Alternative Cα mRNA Expressed Specifically in Spermatogenic Cells

Agustin, Jovenal T. San, Wilkerson, Curtis G., Witman, George B.

cAMP-dependent protein kinase has a central role in the control of mammalian sperm capacitation and motility. Previous protein biochemical studies indicated that the only cAMP-dependent protein...

LC2, the Chlamydomonas Homologue of the t Complex-encoded Protein Tctex2, Is Essential for Outer Dynein Arm Assembly

Pazour, Gregory J., Koutoulis, Anthony, Benashski, Sharon E., Dickert, Bethany L., Sheng, Hong, Patel-King, Ramila S., ...

Tctex2 is thought to be one of the distorter genes of the mouse t haplotype. This complex greatly biases the segregation of the chromosome that carries it such that in heterozygous +/t males, the t...

The Outer Dynein Arm-Docking Complex: Composition and Characterization of a Subunit (Oda1) Necessary for Outer Arm Assembly

Takada, Saeko, Wilkerson, Curtis G., Wakabayashi, Ken-ichi, Kamiya, Ritsu, Witman, George B.

To learn more about how dyneins are targeted to specific sites in the flagellum, we have investigated a factor necessary for binding of outer arm dynein to the axonemal microtubules of Chlamydomonas....

DC3, the 21-kDa Subunit of the Outer Dynein Arm-Docking Complex (ODA-DC), Is a Novel EF-Hand Protein Important for Assembly of Both the Outer Arm and the ODA-DC

Casey, Diane M., Inaba, Kazuo, Pazour, Gregory J., Takada, Saeko, Wakabayashi, Ken-ichi, Wilkerson, Curtis G., ...

The outer dynein arm-docking complex (ODA-DC) is a microtubule-associated structure that targets the outer dynein arm to its binding site on the flagellar axoneme (Takada et al. 2002. Mol. Biol. Cell...

Oda5p, a Novel Axonemal Protein Required for Assembly of the Outer Dynein Arm and an Associated Adenylate KinaseD⃞

Wirschell, Maureen, Pazour, Gregory, Yoda, Akinori, Hirono, Masafumi, Kamiya, Ritsu, Witman, George B.

Of the uncloned ODA genes required for outer dynein arm assembly in Chlamydomonas, ODA5 and ODA10 are of particular interest because they do not encode known subunits of the outer arm or the outer...

A Dynein Light Intermediate Chain, D1bLIC, Is Required for Retrograde Intraflagellar Transport

Hou, Yuqing, Pazour, Gregory J., Witman, George B.

Intraflagellar transport (IFT), the bidirectional movement of particles along flagella, is essential for flagellar assembly. The motor for retrograde IFT in Chlamydomonas is cytoplasmic dynein 1b,...

Novel Role for a Sterol Response Element Binding Protein in Directing Spermatogenic Cell-Specific Gene Expression

Wang, Hang, San Agustin, Jovenal T., Witman, George B., Kilpatrick, Daniel L.

Sperm are highly specialized cells, and their formation requires the synthesis of a large number of unique mRNAs. However, little is known about the transcriptional mechanisms that direct male germ...

Differential Light Chain Assembly Influences Outer Arm Dynein Motor Function

DiBella, Linda M., Gorbatyuk, Oksana, Sakato, Miho, Wakabayashi, Ken-ichi, Patel-King, Ramila S., Pazour, Gregory J., ...

Tctex1 and Tctex2 were originally described as potential distorters/sterility factors in the non-Mendelian transmission of t-haplotypes in mice. These proteins have since been identified as subunits...

The Unique Catalytic Subunit of Sperm cAMP-dependent Protein Kinase Is the Product of an Alternative Cα mRNA Expressed Specifically in Spermatogenic Cells

Agustin, Jovenal T. San, Wilkerson, Curtis G., Witman, George B.

cAMP-dependent protein kinase has a central role in the control of mammalian sperm capacitation and motility. Previous protein biochemical studies indicated that the only cAMP-dependent protein...

LC2, the Chlamydomonas Homologue of the t Complex-encoded Protein Tctex2, Is Essential for Outer Dynein Arm Assembly

Pazour, Gregory J., Koutoulis, Anthony, Benashski, Sharon E., Dickert, Bethany L., Sheng, Hong, Patel-King, Ramila S., ...

Tctex2 is thought to be one of the distorter genes of the mouse t haplotype. This complex greatly biases the segregation of the chromosome that carries it such that in heterozygous +/t males, the t...

The Outer Dynein Arm-Docking Complex: Composition and Characterization of a Subunit (Oda1) Necessary for Outer Arm Assembly

Takada, Saeko, Wilkerson, Curtis G., Wakabayashi, Ken-ichi, Kamiya, Ritsu, Witman, George B.

To learn more about how dyneins are targeted to specific sites in the flagellum, we have investigated a factor necessary for binding of outer arm dynein to the axonemal microtubules of Chlamydomonas....

DC3, the 21-kDa Subunit of the Outer Dynein Arm-Docking Complex (ODA-DC), Is a Novel EF-Hand Protein Important for Assembly of Both the Outer Arm and the ODA-DC

Casey, Diane M., Inaba, Kazuo, Pazour, Gregory J., Takada, Saeko, Wakabayashi, Ken-ichi, Wilkerson, Curtis G., ...

The outer dynein arm-docking complex (ODA-DC) is a microtubule-associated structure that targets the outer dynein arm to its binding site on the flagellar axoneme (Takada et al. 2002. Mol. Biol. Cell...

Oda5p, a Novel Axonemal Protein Required for Assembly of the Outer Dynein Arm and an Associated Adenylate KinaseD⃞

Wirschell, Maureen, Pazour, Gregory, Yoda, Akinori, Hirono, Masafumi, Kamiya, Ritsu, Witman, George B.

Of the uncloned ODA genes required for outer dynein arm assembly in Chlamydomonas, ODA5 and ODA10 are of particular interest because they do not encode known subunits of the outer arm or the outer...

A Dynein Light Intermediate Chain, D1bLIC, Is Required for Retrograde Intraflagellar Transport

Hou, Yuqing, Pazour, Gregory J., Witman, George B.

Intraflagellar transport (IFT), the bidirectional movement of particles along flagella, is essential for flagellar assembly. The motor for retrograde IFT in Chlamydomonas is cytoplasmic dynein 1b,...

Novel Role for a Sterol Response Element Binding Protein in Directing Spermatogenic Cell-Specific Gene Expression

Wang, Hang, San Agustin, Jovenal T., Witman, George B., Kilpatrick, Daniel L.

Sperm are highly specialized cells, and their formation requires the synthesis of a large number of unique mRNAs. However, little is known about the transcriptional mechanisms that direct male germ...

Differential Light Chain Assembly Influences Outer Arm Dynein Motor Function

DiBella, Linda M., Gorbatyuk, Oksana, Sakato, Miho, Wakabayashi, Ken-ichi, Patel-King, Ramila S., Pazour, Gregory J., ...

Tctex1 and Tctex2 were originally described as potential distorters/sterility factors in the non-Mendelian transmission of t-haplotypes in mice. These proteins have since been identified as subunits...

Chlamydomonas reinhardtii hydin is a central pair protein required for flagellar motility

Lechtreck, Karl-Ferdinand, Witman, George B.

Mutations in Hydin cause hydrocephalus in mice, and HYDIN is a strong candidate for causing hydrocephalus in humans. The gene is conserved in ciliated species, including Chlamydomonas reinhardtii. An...

Functional analysis of an individual IFT protein: IFT46 is required for transport of outer dynein arms into flagella

Hou, Yuqing, Qin, Hongmin, Follit, John A., Pazour, Gregory J., Rosenbaum, Joel L., Witman, George B.

Intraflagellar transport (IFT), which is the bidirectional movement of particles within flagella, is required for flagellar assembly. IFT particles are composed of ∼16 proteins, which are organized...

Cytoplasmic dynein nomenclature

Pfister, K. Kevin, Fisher, Elizabeth M.C., Gibbons, Ian R., Hays, Thomas S., Holzbaur, Erika L.F., McIntosh, J. Richard, ...

A variety of names has been used in the literature for the subunits of cytoplasmic dynein complexes. Thus, there is a strong need for a more definitive consensus statement on nomenclature. This is...

Proteomic analysis of a eukaryotic cilium

Pazour, Gregory J., Agrin, Nathan, Leszyk, John, Witman, George B.

Cilia and flagella are widespread cell organelles that have been highly conserved throughout evolution and play important roles in motility, sensory perception, and the life cycles of eukaryotes...

A Dynein Light Chain Is Essential for the Retrograde Particle Movement of Intraflagellar Transport (IFT)

Pazour, Gregory J., Wilkerson, Curtis G., Witman, George B.

Several enzymes, including cytoplasmic and flagellar outer arm dynein, share an Mr 8,000 light chain termed LC8. The function of this chain is unknown, but it is highly conserved between a wide...

The DHC1b (DHC2) Isoform of Cytoplasmic Dynein Is Required for Flagellar Assembly

Pazour, Gregory J., Dickert, Bethany L., Witman, George B.

Dyneins are microtubule-based molecular motors involved in many different types of cell movement. Most dynein heavy chains (DHCs) clearly group into cytoplasmic or axonemal isoforms. However, DHC1b...

The Chlamydomonas reinhardtii ODA3 Gene Encodes a Protein of the Outer Dynein Arm Docking Complex

Koutoulis, Anthony, Pazour, Gregory J., Wilkerson, Curtis G., Inaba, Kazuo, Sheng, Hong, Takada, Saeko, ...

We have used an insertional mutagenesis/ gene tagging technique to generate new Chlamydomonas reinhardtii mutants that are defective in assembly of the outer dynein arm. Among 39 insertional oda...

The intraflagellar transport protein, IFT88, is essential for vertebrate photoreceptor assembly and maintenance

Pazour, Gregory J., Baker, Sheila A., Deane, James A., Cole, Douglas G., Dickert, Bethany L., Rosenbaum, Joel L., ...

Approximately 10% of the photoreceptor outer segment (OS) is turned over each day, requiring large amounts of lipid and protein to be moved from the inner segment to the OS. Defects in...

Chlamydomonas IFT88 and Its Mouse Homologue, Polycystic Kidney Disease Gene Tg737, Are Required for Assembly of Cilia and Flagella

Pazour, Gregory J., Dickert, Bethany L., Vucica, Yvonne, Seeley, E. Scott, Rosenbaum, Joel L., Witman, George B., ...

Intraflagellar transport (IFT) is a rapid movement of multi-subunit protein particles along flagellar microtubules and is required for assembly and maintenance of eukaryotic flagella. We cloned and...

Function and dynamics of PKD2 in Chlamydomonas reinhardtii flagella

Huang, Kaiyao, Diener, Dennis R., Mitchell, Aaron, Pazour, Gregory J., Witman, George B., Rosenbaum, Joel L.

To analyze the function of ciliary polycystic kidney disease 2 (PKD2) and its relationship to intraflagellar transport (IFT), we cloned the gene encoding Chlamydomonas reinhardtii PKD2 (CrPKD2), a...

Mutations in Hydin impair ciliary motility in mice

Lechtreck, Karl-Ferdinand, Delmotte, Philippe, Robinson, Michael L., Sanderson, Michael J., Witman, George B.

Chlamydomonas reinhardtii hydin is a central pair protein required for flagellar motility, and mice with Hydin defects develop lethal hydrocephalus. To determine if defects in Hydin cause...

IC97 Is a Novel Intermediate Chain of I1 Dynein That Interacts with Tubulin and Regulates Interdoublet Sliding

Wirschell, Maureen, Yang, Chun, Yang, Pinfen, Fox, Laura, Yanagisawa, Haru-aki, Kamiya, Ritsu, ...

Our goal is to understand the assembly and regulation of flagellar dyneins, particularly the Chlamydomonas inner arm dynein called I1 dynein. Here, we focus on the uncharacterized I1-dynein IC IC97....