Isw1 chromatin remodeling ATPase coordinates transcription elongation and termination by RNA polymerase II.
We demonstrate that distinct forms of the yeast chromatin-remodeling enzyme Isw1p sequentially regulate each stage of the transcription cycle. The Isw1a complex (Iswlp/Ioc3p) represses gene expression at initiation through specific positioning of a promoter proximal dinucleosome, whereas the Isw1b complex (Iswlp/Ioc2p/Ioc4p) acts within coding regions to control the amount of RNA polymerase (RNAPII) released into productive elongation and to coordinate elongation with termination and pre-mRNA processing. These effects of Isw1b are controlled via phosphorylation of the heptad repeat carboxy-terminal domain (CTD) of RNAPII and methylation of the chromatin template. The transcription elongation factor Spt4p antagonizes Isw1p and overcomes the Isw1p dependent pausing of RNAPII at the onset of the elongation cycle. Overall these studies establish the central role played by Isw1p in the coordination of transcription.
Morillon
Antonin
A
Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
Karabetsou
Nickoletta
N
O'Sullivan
Justin
J
Kent
Nicholas
N
Proudfoot
Nicholas
N
Mellor
Jane
J
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D020868:Gene Silencing; D005800:Genes, Fungal / Q000235:genetics; D006657:Histones / Q000378:metabolism; D008745:Methylation; D009687:Nuclear Proteins / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D011487:Protein Conformation; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors / Q000378:metabolism
D004268:DNA-Binding Proteins; C068394:DST1 protein, S cerevisiae; D006657:Histones; D009687:Nuclear Proteins; D009707:Nucleosomes; D012097:Repressor Proteins; C080991:SPT4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D035602:Transcriptional Elongation Factors; D010768:Phosphoserine; D012319:RNA Polymerase II; D000251:Adenosine Triphosphatases; C470546:ISW1 protein, S cerevisiae