title: Sumoylation of transcription factor Gcn4 facilitates its Srb10-mediated clearance from promoters in yeast.
abstract: The small ubiquitin-related modifier (SUMO) is a conserved factor that post-translationally regulates proteins involved in many cellular processes, including gene transcription. We previously demonstrated that promoter-bound factors become sumoylated during activation of inducible genes in yeast, but the identity of these factors, and the role of sumoylation in their function, was unknown. Here we show that the transcriptional activator Gcn4 is sumoylated on two specific lysine residues and in a manner that depends on its ability to bind DNA, indicating that sumoylation occurs after Gcn4 binding to target promoters. Importantly, this functions to facilitate the subsequent removal of the activator from these promoters after recruitment of RNA polymerase II, which can prevent inappropriate transcription of target genes. Furthermore, we show that clearance of sumoylated Gcn4 requires the protein kinase and Mediator complex subunit Srb10, linking activator removal with target gene transcription. Our study demonstrates an unexpected role for protein sumoylation in the process of transcriptional activation.
authors.affiliation: Department of Biological Sciences, Columbia University, New York, New York 10027, USA.
authors.forename: Emanuel
authors.initials: E
authors.lastname: Rosonina
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Duncan
authors.forename: James L
authors.initials: JL
authors.lastname: Manley
mesh_terms: D001119:Arginase / Q000235:genetics; D050976:Basic-Leucine Zipper Transcription Factors / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D056850:Cyclin-Dependent Kinase 8 / Q000378:metabolism*; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D008239:Lysine / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D058207:Sumoylation
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D002868:Chromosomal Proteins, Non-Histone; C451742:DEF1 protein, S cerevisiae; C501391:GCN4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D056850:Cyclin-Dependent Kinase 8; D018844:Cyclin-Dependent Kinases; C058605:PHO85 protein, S cerevisiae; C498309:SSN3 protein, S cerevisiae; C540423:ARG1 protein, S cerevisiae; D001119:Arginase; D008239:Lysine