The Saccharomyces cerevisiae Cdk8 Mediator Represses AQY1 Transcription by Inhibiting Set1p-Dependent Histone Methylation

摘要

In the budding yeast Saccharomyces cerevisiae, nutrient depletion induces massive transcriptional reprogramming that relies upon communication between transcription factors, post-translational histone modifications, and the RNA polymerase II holoenzyme complex. Histone H3Lys4 methylation (H3Lys4 me), regulated by the -containing COMPASS methyltransferase complex and demethylase, is one of the most well-studied histone modifications. We previously demonstrated that the RNA polymerase II mediator components - inhibit locus-specific H3Lys4 3me independently of . Here, we identify loci subject to - and -dependent histone H3Lys4 3me inhibition using chromatin immunoprecipitation (ChIP)-seq. We further characterized the independent and combined roles of and in controlling H3Lys4 3me and transcription in response to fermentable and nonfermentable carbon at multiple loci. These experiments suggest that H3Lys4 3me alone is insufficient to induce transcription. Interestingly, we identified an unexpected role for - in repressing transcription, an aquaporin whose expression is normally induced during nutrient deprivation. These experiments, combined with previous work in other labs, support a two-step model in which - mediate transcriptional repression by stimulating transcription factor proteolysis and preventing recruitment to the href="http://www.yeastgenome.org/locus/S000006396/overview" data-ga-action="click_feat_suppl" ref="reftype=extlink&article-id=5345701&issue-id=289139&journal-id=1684&FROM=Article%7CFront%20Matter&TO=External%7CLink%7CURI" target="_blank">AQY1 locus.