George B. Spiegelman

Cyclic AMP signalling in Dictyostelium: G-proteins activate separate Ras pathways using specific RasGEFs (2007)

Kae, Helmut, Kortholt, Arjan, Rehmann, Holger, Insall, Robert H., Spiegelman, George B., ...

In general, mammalian Ras guanine nucleotide exchange factors (RasGEFs) show little substrate specificity, although they are often thought to regulate specific pathways. Here, we provide in vitro and...

The Genetic Core of the Universal Ancestor (2003)

Harris, J. Kirk, Kelley, Scott T., Spiegelman, George B., Pace, Norman R.

Molecular analysis of conserved sequences in the ribosomal RNAs of modern organisms reveals a three-domain phylogeny that converges in a universal ancestor for all life. We used the Clusters of...

The modulatory element TNNCT affects transcription of a Drosophila tRNA4al gene without affecting transcription complex stability (1989)

Sajjadi, Fereydoun G., Spiegelman, George B.

We have previously identified a sequence of the general form TNNCT in the 5'-flanking region of a Drosophila melanogaster tRNA4al gene which positively modulates in vitro transcription. The...

Heterologous 5' flanking regions do not support in vitro template activity of a Drosophila melanogaster tRNAVal3b gene (1988)

Mackay, Ron M., Horvath, Daniel, Duncan, Loverne, Spiegelman, George B.

The 5' and 3' structure of a Drosophila tRNAVal3b gene was investigated to examine the defect which caused the extremely low in vitro transcription template activity of the gene. Recombinant genes...

Sequences between the internal control regions of tRNAArg of Drosophila melanogasrer influence stimulation of transcription of the 5' flanking DNA (1988)

Horvath, Daniel, Spiegelman, George B.

Recombinants between 5′ deletion mutants of a tRNAVal3b gene which is inactive as an in vitro transcription template and a CRNAArg gene, which is an active in vitro template were made. The 5′...

Transcription of cloned transfer RNA genes from Drosophila melanogaster in a homologous cell-free extract (1982)

Rajput, Bhanu, Duncan, Loverne, DeMille, Dianne, Miller, Robert C., Spiegelman, George B.

Cloned Drosophila melanogaster tRNA genes have been transcribed in a homologous cell-free extract isolated from a Schneider II cell line. The major product of the reaction is a tRNA precursor which...

DNA strand separation during activation of a developmental promoter by the Bacillus subtilis response regulator Spo0A

Rowe-Magnus, Dean A., Spiegelman, George B.

Spo0A is the central regulator of commitment to sporulation in Bacillus subtilis. Spo0A is a member of the response regulator family of proteins and both represses and stimulates transcription from...

Developmental Gene Expression in Bacillus subtilis crsA47 Mutants Reveals Glucose-Activated Control of the Gene for the Minor Sigma Factor ςH

Dixon, Laurie G., Seredick, Steve, Richer, Martin, Spiegelman, George B.

The presence of excess glucose in growth media prevents normal sporulation of Bacillus subtilis. The crsA47 mutation, located in the gene for the vegetative phase sigma factor (ςA) results in a...

Identification of a Second Region of the Spo0A Response Regulator of Bacillus subtilis Required for Transcription Activation

Rowe-Magnus, Dean A., Richer, Martin J., Spiegelman, George B.

Deletion of the 10 C-terminal amino acids of the Bacillus subtilis response regulator Spo0A or valine substitution at D258 and L260 resulted in a sporulation-negative phenotype and loss of in vivo...

Transcriptional Activation of the Bacillus subtilis spoIIG Promoter by the Response Regulator Spo0A Is Independent of the C-Terminal Domain of the RNA Polymerase Alpha Subunit

Rowe-Magnus, Dean A., Mencía, Mario, Rojo, Fernando, Salas, Margarita, Spiegelman, George B.

In vitro transcription from the spoIIG promoter by Bacillus subtilis RNA polymerase reconstituted with wild-type alpha subunits and with C-terminal deletion mutants of the alpha subunit was equally...

RasC is required for optimal activation of adenylyl cyclase and Akt/PKB during aggregation

Lim, Chinten James, Spiegelman, George B., Weeks, Gerald

Disruption of Dictyostelium rasC, encoding a Ras subfamily protein, generated cells incapable of aggregation. While rasC expression is enriched in a cell type-specific manner during post-aggregative...

Glucose-Resistant Sporulation in Bacillus subtilis crsA47 Mutants Does Not Depend on Promoter Switching at the spo0A Gene

Dixon, Laurie G., Spiegelman, George B.

We have found that sporulation in Bacillus subtilis crsA47 mutants does not require the σH-dependent promoter of the spo0A gene. This implies that the glucose-resistant sporulation phenotype of this...

Culture-Independent Molecular Analysis of Microbial Constituents of the Healthy Human Outer Ear

Frank, Daniel N., Spiegelman, George B., Davis, William, Wagner, Eileen, Lyons, Eric, Pace, Norman R.

Molecular-phylogenetic sequence analyses have provided a new perspective on microbial communities by allowing the detection and identification of constituent microorganisms in the absence of...

Dictyostelium RasD is required for normal phototaxis, but not differentiation

Wilkins, Andrew, Khosla, Meenal, Fraser, Derek J., Spiegelman, George B., Fisher, Paul R., Weeks, Gerald, ...

RasD, a Dictyostelium homolog of mammalian Ras, is maximally expressed during the multicellular stage of development. Normal Dictyostelium aggregates are phototactic and thermotactic, moving towards...

The Genetic Core of the Universal Ancestor

Harris, J. Kirk, Kelley, Scott T., Spiegelman, George B., Pace, Norman R.

Molecular analysis of conserved sequences in the ribosomal RNAs of modern organisms reveals a three-domain phylogeny that converges in a universal ancestor for all life. We used the Clusters of...

Soj Antagonizes Spo0A Activation of Transcription in Bacillus subtilis

McLeod, Brett N., Spiegelman, George B.

The ParA family protein Soj appears to negatively regulate sporulation in Bacillus subtilis by inhibiting transcription from promoters that are activated by phosphorylated Spo0A. We tested in vitro...

A Ras subfamily GTPase shows cell cycle-dependent nuclear localization

Sutherland, Brent W., Spiegelman, George B., Weeks, Gerald

Previously characterized Ras subfamily proteins have been found to be predominantly associated with the plasma membrane where they function in signal transduction pathways to convey extracellular...

Chemoattractant-induced Ras activation during Dictyostelium aggregation

Kae, Helmut, Lim, Chinten James, Spiegelman, George B, Weeks, Gerald

Ras proteins are highly conserved molecular switches that regulate cellular response to external stimuli. Dictyostelium discoideum contains an extensive family of Ras proteins that function in...

Delineation of the Roles Played by RasG and RasC in cAMP-dependent Signal Transduction during the Early Development of Dictyostelium discoideum

Bolourani, Parvin, Spiegelman, George B., Weeks, Gerald

On starvation, the cellular slime mold Dictyostelium discoideum initiates a program of development leading to formation of multicellular structures. The initial cell aggregation requires chemotaxis...

DNA strand separation during activation of a developmental promoter by the Bacillus subtilis response regulator Spo0A

Rowe-Magnus, Dean A., Spiegelman, George B.

Spo0A is the central regulator of commitment to sporulation in Bacillus subtilis. Spo0A is a member of the response regulator family of proteins and both represses and stimulates transcription from...

Developmental Gene Expression in Bacillus subtilis crsA47 Mutants Reveals Glucose-Activated Control of the Gene for the Minor Sigma Factor ςH

Dixon, Laurie G., Seredick, Steve, Richer, Martin, Spiegelman, George B.

The presence of excess glucose in growth media prevents normal sporulation of Bacillus subtilis. The crsA47 mutation, located in the gene for the vegetative phase sigma factor (ςA) results in a...

Identification of a Second Region of the Spo0A Response Regulator of Bacillus subtilis Required for Transcription Activation

Rowe-Magnus, Dean A., Richer, Martin J., Spiegelman, George B.

Deletion of the 10 C-terminal amino acids of the Bacillus subtilis response regulator Spo0A or valine substitution at D258 and L260 resulted in a sporulation-negative phenotype and loss of in vivo...

Transcriptional Activation of the Bacillus subtilis spoIIG Promoter by the Response Regulator Spo0A Is Independent of the C-Terminal Domain of the RNA Polymerase Alpha Subunit

Rowe-Magnus, Dean A., Mencía, Mario, Rojo, Fernando, Salas, Margarita, Spiegelman, George B.

In vitro transcription from the spoIIG promoter by Bacillus subtilis RNA polymerase reconstituted with wild-type alpha subunits and with C-terminal deletion mutants of the alpha subunit was equally...

RasC is required for optimal activation of adenylyl cyclase and Akt/PKB during aggregation

Lim, Chinten James, Spiegelman, George B., Weeks, Gerald

Disruption of Dictyostelium rasC, encoding a Ras subfamily protein, generated cells incapable of aggregation. While rasC expression is enriched in a cell type-specific manner during post-aggregative...

Glucose-Resistant Sporulation in Bacillus subtilis crsA47 Mutants Does Not Depend on Promoter Switching at the spo0A Gene

Dixon, Laurie G., Spiegelman, George B.

We have found that sporulation in Bacillus subtilis crsA47 mutants does not require the σH-dependent promoter of the spo0A gene. This implies that the glucose-resistant sporulation phenotype of this...

Culture-Independent Molecular Analysis of Microbial Constituents of the Healthy Human Outer Ear

Frank, Daniel N., Spiegelman, George B., Davis, William, Wagner, Eileen, Lyons, Eric, Pace, Norman R.

Molecular-phylogenetic sequence analyses have provided a new perspective on microbial communities by allowing the detection and identification of constituent microorganisms in the absence of...

Dictyostelium RasD is required for normal phototaxis, but not differentiation

Wilkins, Andrew, Khosla, Meenal, Fraser, Derek J., Spiegelman, George B., Fisher, Paul R., Weeks, Gerald, ...

RasD, a Dictyostelium homolog of mammalian Ras, is maximally expressed during the multicellular stage of development. Normal Dictyostelium aggregates are phototactic and thermotactic, moving towards...

The Genetic Core of the Universal Ancestor

Harris, J. Kirk, Kelley, Scott T., Spiegelman, George B., Pace, Norman R.

Molecular analysis of conserved sequences in the ribosomal RNAs of modern organisms reveals a three-domain phylogeny that converges in a universal ancestor for all life. We used the Clusters of...

Soj Antagonizes Spo0A Activation of Transcription in Bacillus subtilis

McLeod, Brett N., Spiegelman, George B.

The ParA family protein Soj appears to negatively regulate sporulation in Bacillus subtilis by inhibiting transcription from promoters that are activated by phosphorylated Spo0A. We tested in vitro...

A Ras subfamily GTPase shows cell cycle-dependent nuclear localization

Sutherland, Brent W., Spiegelman, George B., Weeks, Gerald

Previously characterized Ras subfamily proteins have been found to be predominantly associated with the plasma membrane where they function in signal transduction pathways to convey extracellular...

Chemoattractant-induced Ras activation during Dictyostelium aggregation

Kae, Helmut, Lim, Chinten James, Spiegelman, George B, Weeks, Gerald

Ras proteins are highly conserved molecular switches that regulate cellular response to external stimuli. Dictyostelium discoideum contains an extensive family of Ras proteins that function in...

Delineation of the Roles Played by RasG and RasC in cAMP-dependent Signal Transduction during the Early Development of Dictyostelium discoideum

Bolourani, Parvin, Spiegelman, George B., Weeks, Gerald

On starvation, the cellular slime mold Dictyostelium discoideum initiates a program of development leading to formation of multicellular structures. The initial cell aggregation requires chemotaxis...

Transcription Modulation of Salmonella enterica Serovar Typhimurium Promoters by Sub-MIC Levels of Rifampin▿

Yim, Grace, De La Cruz, Fernando, Spiegelman, George B., Davies, Julian

Promoter-lux fusions that showed rifampin-modulated transcription were identified from a Salmonella enterica serovar Typhimurium 14028 reporter library. The transformation of a subset of fusions into...

Cyclic AMP signalling in Dictyostelium: G-proteins activate separate Ras pathways using specific RasGEFs

Kae, Helmut, Kortholt, Arjan, Rehmann, Holger, Insall, Robert H, Spiegelman, George B, ...

In general, mammalian Ras guanine nucleotide exchange factors (RasGEFs) show little substrate specificity, although they are often thought to regulate specific pathways. Here, we provide in vitro and...