Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RAP1 is a sequence-specific DNA-binding protein essential for cell growth. The occurrence of RAP1-binding sites in many promoter regions, the mating-type gene silencer elements, and telomeres suggests that RAP1 has multiple functions in the cell. To assess its role in transcription, temperature-sensitive mutations in RAP1 were generated. Analysis of rap1ts strains provides evidence that RAP1 functions in both transcriptional activation and silencing of mating-type genes. Several observations indicate that rap1ts strains are defective in the expression of MAT alpha, whose upstream activation sequence (UAS) contains a RAP1-binding site. At nonpermissive temperatures, decreases in MAT alpha steady-state transcript levels can be detected in MAT alpha rap1ts strains. Furthermore, these strains are deficient in alpha-pheromone production and simultaneously express at least two alpha-specific genes. These phenotypes can be reversed by replacing the RAP1-binding site at MAT alpha with a binding site for the GAL4 transcriptional activator. Certain rap1ts alleles have an opposite effect on the silent mating-type locus HMR, which becomes partially derepressed at nonpermissive temperatures.
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PMID:RAP1 protein activates and silences transcription of mating-type genes in yeast. 201 87

Our studies using proteases to probe protein structure establish that binding to the upstream activating sequences (UASs) of two different yeast a-specific genes induces a conformational change in the pheromone/receptor transcription factor (PRTF), which is not observed upon binding to the UASs of either of two alpha-specific genes. We propose that this selective structural alteration exposes an activation region of PRTF when it binds a-specific genes, switching these genes on. The transcriptional activator MAT alpha 1 may activate alpha-specific genes by binding to the PRTF-alpha-specific UAS complex and unmasking the otherwise hidden activation surface of PRTF. We also show that the N-terminal third of PRTF is sufficient for specific DNA binding, while the middle third of the protein interacts with MAT alpha 1.
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PMID:DNA binding-induced conformational change of the yeast transcriptional activator PRTF. 216 91

We previously reported the isolation of yeast mutants that seem to affect the function of certain autonomously replicating sequences (ARSs). These mutants are known as mcm for their defect in the maintenance of minichromosomes. We have now characterized in more detail one ARS-specific mutation, mcm1-1. This Mcm1 mutant has a second phenotype; MAT alpha mcm1-1 strains are sterile. MCM1 is non-allelic to other known alpha-specific sterile mutations and, unlike most genes required for mating, it is essential for growth. The alpha-specific sterile phenotype of the mcm1-1 mutant is manifested by its failure to produce a normal amount of the mating pheromone, alpha-factor. In addition, transcripts of the MF alpha 1 and STE3 genes, which encode the alpha-factor precursor and the alpha-factor receptor, respectively, are greatly reduced in this mutant. These and other properties of the mcm1-1 mutant suggest that the MCM1 protein may act as a transcriptional activator of alpha-specific genes. We have cloned, mapped and sequenced the wild-type and mutant alleles of MCM1, which is located on the right arm of chromosome XIII near LYS7. The MCM1 gene product is a protein of 286 amino acid residues and contains an unusual region in which 19 out of 20 residues are either aspartic or glutamic acid, followed by a series of glutamine tracts. MCM1 has striking homology to ARG80, a regulatory gene of the arginine metabolic pathway located about 700 base-pairs upstream from MCM1. A substitution of leucine for proline at amino acid position 97, immediately preceding the polyanionic region, was shown to be responsible for both the alpha-specific sterile and minichromosome-maintenance defective phenotypes of the mcm1-1 mutant.
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PMID:Saccharomyces cerevisiae protein involved in plasmid maintenance is necessary for mating of MAT alpha cells. 306 8

Homothallic strains of Saccharomyces cerevisiae can change mating type as often as every generation by replacing the allele at the MAT locus with a copy of mating type information present at one of two storage loci, HML and HMR, located on either end of chromosome III. Selection of the appropriate donor locus is dictated by a mating type-specific repressor protein, alpha2p: Cells containing alpha2p select HMR, whereas those lacking alpha2p select HML. As a repressor protein, alpha2p binds to DNA cooperatively with the transcriptional activator Mcm1p. Here we show that two alpha2p/Mcm1p-binding sites, DPS1 and DPS2, control donor selection. DPS1 and DPS2 are located approximately 30 kb from the left arm of chromosome III, well removed from HML, HMR, and MAT. Precise deletion of only DPS1 and DPS2 results in random selection of donor loci and in a cells without affecting selection in alpha cells. Reciprocally, deletion of only the alpha2p binding segments in each of these two sites results in selection of the wrong donor loci in alpha cells without affecting preference in a cells. These results suggest that Mcm1p, bound to these two sites in the absence of alpha2p, activates HML as donor. Binding of alpha2p blocks the ability of Mcm1p bound to DPS1 and DPS2 to activate HML, resulting in default selection of HMR as donor. DPS1 and DPS2 also regulate expression of several noncoding RNAs, although deletion of at least one of these RNA loci does not affect donor preference. This suggests that transcriptional activation, rather than transcription of a specific product, is the initiating event in activating the left arm of chromosome III for donor selection.
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PMID:Alpha2p controls donor preference during mating type interconversion in yeast by inactivating a recombinational enhancer of chromosome III. 927 Nov 14

IME1 encodes a transcriptional activator required for the transcription of meiosis-specific genes and initiation of meiosis in Saccharomyces cerevisiae. The transcription of IME1 is repressed in the presence of glucose, and a low basal level of IME1 RNA is observed in vegetative cultures with acetate as the sole carbon source. Upon nitrogen depletion a transient induction in the transcription of IME1 is observed in MATa/MATalpha diploids but not in MAT-insufficient strains. In this study we demonstrate that the transcription of IME1 is controlled by an extremely unusual large 5' region, over 2,100 bp long. This area is divided into four different upstream controlling sequences (UCS). UCS2 promotes the transcription of IME1 in the presence of a nonfermentable carbon source. UCS2 is flanked by three negative regions: UCS1, which exhibits URS activity in the presence of nitrogen, and UCS3 and UCS4, which repress the activity of UCS2 in MAT-insufficient cells. UCS2 consists of alternate positive and negative elements: three distinct constitutive URS elements that prevent the function of any upstream activating sequence (UAS) under all growth conditions, a constitutive UAS element that promotes expression under all growth conditions, a UAS element that is active only in vegetative media, and two discrete elements that function as UASs in the presence of acetate. Sequence analysis of IME1 revealed the presence of two almost identical 30- to 32-bp repeats. Surprisingly, one repeat, IREd, exhibits constitutive URS activity, whereas the other repeat, IREu, serves as a carbon-source-regulated UAS element. The RAS-cyclic AMP-dependent protein kinase cAPK pathway prevents the UAS activity of IREu in the presence of glucose as the sole carbon source, while the transcriptional activators Msn2p and Msn4p promote the UAS activity of this repeat in the presence of acetate. We suggest that the use of multiple negative and positive elements is essential to restrict transcription to the appropriate conditions and that the combinatorial effect of the entire region leads to the regulated transcription of IME1.
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PMID:Multiple and distinct activation and repression sequences mediate the regulated transcription of IME1, a transcriptional activator of meiosis-specific genes in Saccharomyces cerevisiae. 952 70