title: Novel role for mediator complex subunit Srb5/Med18 in termination of transcription.
abstract: Mediator complex functions at the recruitment as well as the post-recruitment steps of transcription. Here we provide evidence for a novel role of Mediator in termination of transcription. Mediator subunit Srb5/Med18 cross-links to the 5' and 3' ends of INO1 and CHA1. In srb5(-) cells, recruitment of TATA-binding protein (TBP) and transcription factor IIB (TFIIB) onto the promoter of these genes remained unaffected, but cross-linking of the cleavage-polyadenylation factors Rna15 and Pta1 toward the 3' end of genes was compromised. In these cells, RNA polymerase II accumulated near the 3' end of genes and beyond. Transcription run-on analysis confirmed a transcription readthrough phenotype in the absence of Srb5/Med18. These results strongly suggest that Mediator subunit Srb5/Med18 is required for proper termination of transcription of a subset of genes in budding yeast.
authors.affiliation: Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202, USA.
authors.forename: Banupriya
authors.initials: B
authors.lastname: Mukundan
authors.forename: Athar
authors.initials: A
authors.lastname: Ansari
mesh_terms: D056892:Mediator Complex / Q000235:genetics / Q000378:metabolism*; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology*
chemical_list: D056892:Mediator Complex; C082149:SRB5 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D012319:RNA Polymerase II