scholarly journals Interaction of yeast repressor-activator protein Ume6p with glycogen synthase kinase 3 homolog Rim11p.

1997 ◽  
Vol 17 (12) ◽  
pp. 7230-7236 ◽  
Author(s):  
K Malathi ◽  
Y Xiao ◽  
A P Mitchell
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Glycogen Synthase ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
Amino Acid Substitutions ◽  
Activation Domain ◽  
Yeast Saccharomyces Cerevisiae ◽  
Transcriptional Activation Domain

Meiosis and expression of early meiotic genes in the budding yeast Saccharomyces cerevisiae depend upon Rim11p, Ume6p, and Ime1p. Rim11p (also called Mds1p and ScGSK3) is a protein kinase related to glycogen synthase kinase 3 (GSK3); Ume6p is an architectural transcription factor; and Imelp is a Ume6p-binding protein that provides a transcriptional activation domain. Rim11p is required for Ime1p-Ume6p interaction, and prior studies have shown that Rim11p binds to and phosphorylates Ime1p. We show here that Rim11p binds to and phosphorylates Ume6p, as well. Amino acid substitutions in Ume6p that alter a consensus GSK3 site reduce or abolish Rim11p-Ume6p interaction and Rim11p-dependent phosphorylation, and they cause defects in interaction between Ume6p and Ime1p and in meiotic gene expression. Therefore, interaction between Rim11p and Ume6p, resulting in phosphorylation of Ume6p, is required for Ime1p-Ume6p complex formation. Rim11p, like metazoan GSK3beta, phosphorylates both interacting subunits of a target protein complex.

scholarly journals Fos and jun cooperate in transcriptional regulation via heterologous activation domains.

1990 ◽  
Vol 10 (10) ◽  
pp. 5532-5535 ◽  
Author(s):  
C Abate ◽  
D Luk ◽  
E Gagne ◽  
R G Roeder ◽  
T Curran
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Regulation Of Gene Expression ◽  
Negative Influence ◽  
Activation Domain ◽  
Activation Domains ◽  
Transcriptional Activation Domain ◽  
Transcriptional Stimulation

The products of c-fos and c-jun (Fos and Jun) function in gene regulation by interacting with the AP-1 binding site. Here we have examined the contribution of Fos and Jun toward transcriptional activity by using Fos and Jun polypeptides purified from Escherichia coli. Fos contained a transcriptional activation domain as well as a region which exerted a negative influence on transcriptional activity in vitro. Moreover, distinct activation domains in both Fos and Jun functioned cooperatively in transcriptional stimulation. Thus, regulation of gene expression by Fos and Jun results from an integration of several functional domains in a bimolecular complex.

scholarly journals Transcriptional activation upon pheromone stimulation mediated by a small domain of Saccharomyces cerevisiae Ste12p.

1997 ◽  
Vol 17 (11) ◽  
pp. 6410-6418 ◽  
Author(s):  
H Pi ◽  
C T Chien ◽  
S Fields
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Map Kinase ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Activation Domain ◽  
Yeast Saccharomyces Cerevisiae ◽  
Activation Domains ◽  
Hybrid Proteins ◽  
High Level ◽  
Transcriptional Induction

In the yeast Saccharomyces cerevisiae, Ste12p induces transcription of pheromone-responsive genes by binding to a DNA sequence designated the pheromone response element. We generated a series of hybrid proteins of Ste12p with the DNA-binding and activation domains of the transcriptional activator Gal4p to define a pheromone induction domain of Ste12p sufficient to mediate pheromone-induced transcription by these hybrid proteins. A minimal pheromone induction domain, delineated as residues 301 to 335 of Ste12p, is dependent on the pheromone mitogen-activated protein (MAP) kinase pathway for induction activity. Mutation of the three serine and threonine residues within the minimal pheromone induction domain did not affect transcriptional induction, indicating that the activity of this domain is not directly regulated by MAP kinase phosphorylation. By contrast, mutation of the two tyrosines or their preceding acidic residues led to a high level of transcriptional activity in the absence of pheromone and consequently to the loss of pheromone induction. This constitutively high activity was not affected by mutations in the MAP kinase cascade, suggesting that the function of the pheromone induction domain is normally repressed in the absence of pheromone. By two-hybrid analysis, this minimal domain interacts with two negative regulators, Dig1p and Dig2p (also designated Rst1p and Rst2p), and the interaction is abolished by mutation of the tyrosines. The pheromone induction domain itself has weak and inducible transcriptional activity, and its ability to potentiate transcription depends on the activity of an adjacent activation domain. These results suggest that the pheromone induction domain of Ste12p mediates transcriptional induction via a two-step process: the relief of repression and synergistic transcriptional activation with another activation domain.

scholarly journals Yeast Glycogen Synthase Kinase-3 Activates Msn2p-dependent Transcription of Stress Responsive Genes

2003 ◽  
Vol 14 (1) ◽  
pp. 302-312 ◽  
Author(s):  
Yuzoh Hirata ◽  
Tomoko Andoh ◽  
Toshimasa Asahara ◽  
Akira Kikuchi
Keyword(s):  
Double Mutant ◽  
Glycogen Synthase ◽  
Binding Activity ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
Growth Defect ◽  
Transcriptional Level ◽  
Null Mutant ◽  
Promoter Regions ◽  
Yeast Saccharomyces Cerevisiae

The yeast Saccharomyces cerevisiae has four genes,MCK1, MDS1 (RIM11),MRK1, and YOL128c, that encode homologues of mammalian glycogen synthase kinase 3 (GSK-3). A gsk-3null mutant in which these four genes are disrupted showed growth defects on galactose medium. We isolated several multicopy suppressors of this growth defect. Two of them encoded Msn2p and phosphoglucomutase (PGM). Msn2p is a transcription factor that binds to the stress-response element (STRE). PGM is an enzyme that interconverts glucose-1 phosphate and glucose-6 phosphate and is regulated by Msn2p at the transcriptional level. Expression of the mRNAs ofPGM2 and DDR2, whose promoter regions possess STRE sequences, on induction by heat shock or salt stress was reduced not only in an msn2 msn4 (msn2homologue) double mutant but also in the gsk-3 null mutant. STRE-dependent transcription was greatly inhibited in thegsk-3 null mutant or mck1 mds1 double mutant, and this phenotype was suppressed by the expression of Mck1p but not of a kinase-inactive form of Mck1p. Although Msn2p accumulated in the nucleus of the gsk-3 null mutant as well as in the wild-type strain under various stress conditions, its STRE-binding activity was reduced in extracts prepared from the gsk-3null mutant or mck1 mds1 double mutant. These results suggest that yeast GSK-3 promotes formation of a complex between Msn2p and DNA, which is required for the proper response to different forms of stress. Because neither Msn2p–GSK-3 complex formation nor GSK-3–dependent phosphorylation of Msn2p could be detected, the regulation of Msn2p by GSK-3 may be indirect.

Fos and jun cooperate in transcriptional regulation via heterologous activation domains

1990 ◽  
Vol 10 (10) ◽  
pp. 5532-5535
Author(s):  
C Abate ◽  
D Luk ◽  
E Gagne ◽  
R G Roeder ◽  
T Curran
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Regulation Of Gene Expression ◽  
Negative Influence ◽  
Activation Domain ◽  
Activation Domains ◽  
Transcriptional Activation Domain ◽  
Transcriptional Stimulation

The products of c-fos and c-jun (Fos and Jun) function in gene regulation by interacting with the AP-1 binding site. Here we have examined the contribution of Fos and Jun toward transcriptional activity by using Fos and Jun polypeptides purified from Escherichia coli. Fos contained a transcriptional activation domain as well as a region which exerted a negative influence on transcriptional activity in vitro. Moreover, distinct activation domains in both Fos and Jun functioned cooperatively in transcriptional stimulation. Thus, regulation of gene expression by Fos and Jun results from an integration of several functional domains in a bimolecular complex.

scholarly journals Gene Activation by Dissociation of an Inhibitor from a Transcriptional Activation Domain

2009 ◽  
Vol 29 (20) ◽  
pp. 5604-5610 ◽  
Author(s):  
Fenglei Jiang ◽  
Benjamin R. Frey ◽  
Margery L. Evans ◽  
Jordan C. Friel ◽  
James E. Hopper
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Fluorescent Protein ◽  
Gene Activation ◽  
Gene Array ◽  
Strong Support ◽  
Live Cells ◽  
Activation Domain ◽  
Transcriptional Activation Domain ◽  
Gene Switch

ABSTRACT Gal4 is a prototypical eukaryotic transcriptional activator whose recruitment function is inhibited in the absence of galactose by the Gal80 protein through masking of its transcriptional activation domain (AD). A long-standing nondissociation model posits that galactose-activated Gal3 interacts with Gal4-bound Gal80 at the promoter, yielding a tripartite Gal3-Gal80-Gal4 complex with altered Gal80-Gal4 conformation to enable Gal4 AD activity. Some recent data challenge this model, whereas other recent data support the model. To address this controversy, we imaged fluorescent-protein-tagged Gal80, Gal4, and Gal3 in live cells containing a novel GAL gene array. We find that Gal80 rapidly dissociates from Gal4 in response to galactose. Importantly, this dissociation is Gal3 dependent and concurrent with Gal4-activated GAL gene expression. When galactose-triggered dissociation is followed by galactose depletion, preexisting Gal80 reassociates with Gal4, indicating that sequestration of Gal80 by Gal3 contributes to the observed Gal80-Gal4 dissociation. Moreover, the ratio of nuclear Gal80 to cytoplasmic Gal80 decreases in response to Gal80-Gal3 interaction. Taken together, these and other results provide strong support for a GAL gene switch model wherein Gal80 rapidly dissociates from Gal4 through a mechanism that involves sequestration of Gal80 by galactose-activated Gal3.

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