Kin28 regulates the transient association of Mediator with core promoters.
Mediator is an essential, broadly used eukaryotic transcriptional coactivator. How and what Mediator communicates from activators to RNA polymerase II (RNAPII) remains an open question. Here we performed genome-wide location profiling of Saccharomyces cerevisiae Mediator subunits. Mediator is not found at core promoters but rather occupies the upstream activating sequence, upstream of the pre-initiation complex. In the absence of Kin28 (CDK7) kinase activity or in cells in which the RNAPII C-terminal domain is mutated to replace Ser5 with alanine, however, Mediator accumulates at core promoters together with RNAPII. We propose that Mediator is released quickly from promoters after phosphorylation of Ser5 by Kin28 (CDK7), which also allows for RNAPII to escape from the promoter.
Institut de recherches cliniques de Montréal, Montréal, Québec, Canada.
Célia
C
Jeronimo
1] Institut de recherches cliniques de Montréal, Montréal, Québec, Canada. [2] Département de Médecine, Université de Montréal, Montréal, Québec, Canada.
François
F
Robert
D018844:Cyclin-Dependent Kinases / Q000502:physiology*; D056892:Mediator Complex / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D008957:Models, Genetic; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000378:metabolism / Q000502:physiology; D012045:Regulatory Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*; D012694:Serine / Q000737:chemistry; D014158:Transcription, Genetic / Q000502:physiology
D056892:Mediator Complex; D029701:Saccharomyces cerevisiae Proteins; D012694:Serine; D018844:Cyclin-Dependent Kinases; C084210:Kin28 protein kinase, S cerevisiae; D012319:RNA Polymerase II