title: RNA polymerase III under control: repression and de-repression.
abstract: The synthesis of tRNA by yeast RNA polymerase III (Pol III) is regulated in response to changing environmental conditions. This control is mediated by Maf1, the global negative regulator of Pol III transcription conserved from yeast to humans. Details regarding the molecular basis of Pol III repression by Maf1 are now emerging from recently reported structural and biochemical data on Pol III and Maf1. Efficient Pol III transcription, following the shift of cells from a non-fermentable carbon source to glucose, requires phosphorylation of Maf1. One of the newly identified Maf1 kinases is the chromatin-bound casein kinase II (CK2). Current studies have allowed us to propose an innovative mechanism of Pol III regulation. We suggest that CK2-mediated phosphorylation of Maf1, occurring directly on tDNA chromatin, controls Pol III recycling.
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland. magda@ibb.waw.pl
authors.forename: Magdalena
authors.initials: M
authors.lastname: Boguta
authors.forename: Damian
authors.initials: D
authors.lastname: Graczyk
mesh_terms: D047390:Casein Kinase II / Q000235:genetics / Q000378:metabolism; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D004794:Enzyme Repression; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012320:RNA Polymerase III / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D002843:Chromatin; C104954:MAF1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D012343:RNA, Transfer; D047390:Casein Kinase II; D012320:RNA Polymerase III