scholarly journals TFG/TAF30/ANC1, a component of the yeast SWI/SNF complex that is similar to the leukemogenic proteins ENL and AF-9.

1996 ◽  
Vol 16 (7) ◽  
pp. 3308-3316 ◽  
Author(s):  
B R Cairns ◽  
N L Henry ◽  
R D Kornberg

The SWI1/ADR6, SWI2/SNF2, SWI3, SNF5, and SNF6 gene products are all required for proper transcriptional control of many genes in the yeast Saccharomyces cerevisiae. Genetic studies indicated that these gene products might form a multiprotein SWI/SNF complex important for chromatin transitions preceding transcription from RNA polymerase II promoters. Biochemical studies identified a SWI/SNF complex containing these and at least six additional polypeptides. Here we show that the 29-kDa component of the SWI/SNF complex is identical to TFG3/TAF30/ANC1. Thus, a component of the SWI/SNF complex is also a member of the TFIIF and TFIID transcription complexes. TFG3 interacted with the SNF5 component of the SWI/SNF complex in protein interaction blots. TFG3 is significantly similar to ENL and AF-9, two proteins implicated in human acute leukemia. These results suggest that ENL and AF-9 proteins interact with the SNF5 component of the human SWI/SNF complex and raise the possibility that the SWI/SNF complex is involved in acute leukemia.

Nucleotide excision repair (ner) in eukaryotes is a biochemically complex process involving multiple gene products. The budding yeast Saccharomyces cerevisiae is an informative model for this process. Multiple genes and in some cases gene products that are indispensable for ner have been isolated from this organism. Homologues of many of these yeast genes are structurally and functionally conserved in higher organisms, including humans. The yeast Rad1/Rad10 heterodimeric protein complex is an endonuclease that is believed to participate in damage-specific incision of DNA during ner . This endonuclease is also required for specialized types of recombination. The products of the RAD3, SSL2(RAD25) SSL1 and TFB1 genes have dual roles in ner and in RNA polymerase II-dependent basal transcription.


Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 737-747 ◽  
Author(s):  
Jacques Archambault ◽  
David B Jansma ◽  
James D Friesen

Abstract In the yeast Saccharomyces cerevisiae, mutations in genes encoding subunits of RNA polymerase II (RNAPII) often give rise to a set of pleiotropic phenotypes that includes temperature sensitivity, slow growth and inositol auxotrophy. In this study, we show that these phenotypes can be brought about by a reduction in the intracellular concentration of RNAPII. Underproduction of RNAPII was achieved by expressing the gene (RPO21), encoding the largest subunit of the enzyme, from the LEU2 promoter or a weaker derivative of it, two promoters that can be repressed by the addition of leucine to the growth medium. We found that cells that underproduced RPO21 were unable to derepress fully the expression of a reporter gene under the control of the INO1 UAS. Our results indicate that temperature sensitivity, slow growth and inositol auxotrophy is a set of phenotypes that can be caused by lowering the steady-state amount of RNAPII; these results also lead to the prediction that some of the previously identified RNAPII mutations that confer this same set of phenotypes affect the assembly/stability of the enzyme. We propose a model to explain the hypersensitivity of INO1 transcription to mutations that affect components of the RNAPII transcriptional machinery.


1986 ◽  
Vol 6 (2) ◽  
pp. 688-702 ◽  
Author(s):  
J M Ivy ◽  
A J Klar ◽  
J B Hicks

Mating type in the yeast Saccharomyces cerevisiae is determined by the MAT (a or alpha) locus. HML and HMR, which usually contain copies of alpha and a mating type information, respectively, serve as donors in mating type interconversion and are under negative transcriptional control. Four trans-acting SIR (silent information regulator) loci are required for repression of transcription. A defect in any SIR gene results in expression of both HML and HMR. The four SIR genes were isolated from a genomic library by complementation of sir mutations in vivo. DNA blot analysis suggests that the four SIR genes share no sequence homology. RNA blots indicate that SIR2, SIR3, and SIR4 each encode one transcript and that SIR1 encodes two transcripts. Null mutations, made by replacement of the normal genomic allele with deletion-insertion mutations created in the cloned SIR genes, have a Sir- phenotype and are viable. Using the cloned genes, we showed that SIR3 at a high copy number is able to suppress mutations of SIR4. RNA blot analysis suggests that this suppression is not due to transcriptional regulation of SIR3 by SIR4; nor does any SIR4 gene transcriptionally regulate another SIR gene. Interestingly, a truncated SIR4 gene disrupts regulation of the silent mating type loci. We propose that interaction of at least the SIR3 and SIR4 gene products is involved in regulation of the silent mating type genes.


1996 ◽  
Vol 16 (6) ◽  
pp. 2719-2727 ◽  
Author(s):  
S Silve ◽  
P Leplatois ◽  
A Josse ◽  
P H Dupuy ◽  
C Lanau ◽  
...  

SR 31747 is a novel immunosuppressant agent that arrests cell proliferation in the yeast Saccharomyces cerevisiae, SR 31747-treated cells accumulate the same aberrant sterols as those found in a mutant impaired in delta 8- delta 7-sterol isomerase. Sterol isomerase activity is also inhibited by SR 31747 in in vitro assays. Overexpression of the sterol isomerase-encoding gene, ERG2, confers enhanced SR resistance. Cells growing anaerobically on ergosterol-containing medium are not sensitive to SR. Disruption of the sterol isomerase-encoding gene is lethal in cells growing in the absence of exogenous ergosterol, except in SR-resistant mutants lacking either the SUR4 or the FEN1 gene product. The results suggest that sterol isomerase is the target of SR 31747 and that both the SUR4 and FEN1 gene products are required to mediate the proliferation arrest induced by ergosterol depletion.


Genes ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 462 ◽  
Author(s):  
Janet Taggart ◽  
Yirong Wang ◽  
Erin Weisenhorn ◽  
Colin W. MacDiarmid ◽  
Jason Russell ◽  
...  

Zinc homeostasis is essential for all organisms. The Zap1 transcriptional activator regulates these processes in the yeast Saccharomyces cerevisiae. During zinc deficiency, Zap1 increases expression of zinc transporters and proteins involved in adapting to the stress of zinc deficiency. Transcriptional activation by Zap1 can also repress expression of some genes, e.g., RTC4. In zinc-replete cells, RTC4 mRNA is produced with a short transcript leader that is efficiently translated. During deficiency, Zap1-dependent expression of an RNA with a longer transcript leader represses the RTC4 promoter. This long leader transcript (LLT) is not translated due to the presence of small open reading frames upstream of the RTC4 coding region. In this study, we show that the RTC4 LLT RNA also plays a second function, i.e., repression of the adjacent GIS2 gene. In generating the LLT transcript, RNA polymerase II transcribes RTC4 through the GIS2 promoter. Production of the LLT RNA correlates with the decreased expression of GIS2 mRNA and mutations that prevent synthesis of the LLT RNA or terminate it before the GIS2 promoter renders GIS2 mRNA expression and Gis2 protein accumulation constitutive. Thus, we have discovered an unusual regulatory mechanism that uses a bicistronic RNA to control two genes simultaneously.


2020 ◽  
Vol 48 (10) ◽  
pp. 5407-5425 ◽  
Author(s):  
Katarzyna Kaczmarek Michaels ◽  
Salwa Mohd Mostafa ◽  
Julia Ruiz Capella ◽  
Claire L Moore

Abstract Adjusting DNA structure via epigenetic modifications, and altering polyadenylation (pA) sites at which precursor mRNA is cleaved and polyadenylated, allows cells to quickly respond to environmental stress. Since polyadenylation occurs co-transcriptionally, and specific patterns of nucleosome positioning and chromatin modifications correlate with pA site usage, epigenetic factors potentially affect alternative polyadenylation (APA). We report that the histone H3K4 methyltransferase Set1, and the histone H3K36 methyltransferase Set2, control choice of pA site in Saccharomyces cerevisiae, a powerful model for studying evolutionarily conserved eukaryotic processes. Deletion of SET1 or SET2 causes an increase in serine-2 phosphorylation within the C-terminal domain of RNA polymerase II (RNAP II) and in the recruitment of the cleavage/polyadenylation complex, both of which could cause the observed switch in pA site usage. Chemical inhibition of TOR signaling, which causes nutritional stress, results in Set1- and Set2-dependent APA. In addition, Set1 and Set2 decrease efficiency of using single pA sites, and control nucleosome occupancy around pA sites. Overall, our study suggests that the methyltransferases Set1 and Set2 regulate APA induced by nutritional stress, affect the RNAP II C-terminal domain phosphorylation at Ser2, and control recruitment of the 3′ end processing machinery to the vicinity of pA sites.


2001 ◽  
Vol 21 (17) ◽  
pp. 5790-5796 ◽  
Author(s):  
Olivier Vincent ◽  
Sergei Kuchin ◽  
Seung-Pyo Hong ◽  
Robert Townley ◽  
Valmik K. Vyas ◽  
...  

ABSTRACT Sip4 is a Zn2Cys6 transcriptional activator that binds to the carbon source-responsive elements of gluconeogenic genes in Saccharomyces cerevisiae. The Snf1 protein kinase interacts with Sip4 and regulates its phosphorylation and activator function in response to glucose limitation; however, evidence suggested that another kinase also regulates Sip4. Here we examine the role of the Srb10 kinase, a component of the RNA polymerase II holoenzyme that has been primarily implicated in transcriptional repression but also positively regulates Gal4. We show that Srb10 is required for phosphorylation of Sip4 during growth in nonfermentable carbon sources and that the catalytic activity of Srb10 stimulates the ability of LexA-Sip4 to activate transcription of a reporter. Srb10 and Sip4 coimmunoprecipitate from cell extracts and interact in two-hybrid assays, suggesting that Srb10 regulates Sip4 directly. We also present evidence that the Srb10 and Snf1 kinases interact with different regions of Sip4. These findings support the view that the Srb10 kinase not only plays negative roles in transcriptional control but also has broad positive roles during growth in carbon sources other than glucose.


2000 ◽  
Vol 28 (4) ◽  
pp. 499-504 ◽  
Author(s):  
A. Baker ◽  
W. Charlton ◽  
B. Johnson ◽  
E. Lopez-Huertas ◽  
J. Oh ◽  
...  

Peroxisomes are eukaryotic organelles that perform diverse and variable functions. Although genetic studies in yeasts and mammals have identified approximately 20 genes (PEX genes) required for the biogenesis of this important organelle, biochemical studies of protein targeting and import have lagged behind and in many cases we have no idea of the function of the PEX gene products (peroxins). Using an import assay in vitro derived from sunflower cotyledon cells and recombinant proteins, we have obtained translocation intermediates on the peroxisome import pathway and are using cross-linking to identify interacting partners. We have also used antibodies raised against human PEX14 to inhibit the import of matrix proteins in this system. To obtain homologous antibodies for inhibition experiments, to immunoprecipitate cross-linked products and to enable us to study the import pathways of peroxins we have cloned and characterized plant orthologues of three PEX genes, PEX6, PEX10 and PEX14.


1990 ◽  
Vol 10 (5) ◽  
pp. 2269-2284 ◽  
Author(s):  
D Herrick ◽  
R Parker ◽  
A Jacobson

We developed a procedure to measure mRNA decay rates in the yeast Saccharomyces cerevisiae and applied it to the determination of half-lives for 20 mRNAs encoded by well-characterized genes. The procedure utilizes Northern (RNA) or dot blotting to quantitate the levels of individual mRNAs after thermal inactivation of RNA polymerase II in an rpb1-1 temperature-sensitive mutant. We compared the results of this procedure with results obtained by two other procedures (approach to steady-state labeling and inhibition of transcription with Thiolutin) and also evaluated whether heat shock alter mRNA decay rates. We found that there are no significant differences in the mRNA decay rates measured in heat-shocked and non-heat-shocked cells and that, for most mRNAs, different procedures yield comparable relative decay rates. Of the 20 mRNAs studied, 11, including those encoded by HIS3, STE2, STE3, and MAT alpha 1, were unstable (t1/2 less than 7 min) and 4, including those encoded by ACT1 and PGK1, were stable (t1/2 greater than 25 min). We have begun to assess the basis and significance of such differences in the decay rates of these two classes of mRNA. Our results indicate that (i) stable and unstable mRNAs do not differ significantly in their poly(A) metabolism; (ii) deadenylation does not destabilize stable mRNAs; (iii) there is no correlation between mRNA decay rate and mRNA size; (iv) the degradation of both stable and unstable mRNAs depends on concomitant translational elongation; and (v) the percentage of rare codons present in most unstable mRNAs is significantly higher than in stable mRNAs.


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