The Paf1 complex has functions independent of actively transcribing RNA polymerase II.
The yeast Paf1 complex, minimally composed of Paf1, Ctr9, Cdc73, Rtf1, and Leo1, was originally isolated in association with RNA polymerase II (Pol II). Paf1 complex components are abundant and colocalize with Pol II on chromatin at promoters and in the coding regions of actively transcribed genes. Loss of Paf1 results in severe phenotypes and reduced amounts of other Paf1 factors, with little effect on abundance or chromatin distribution of Pol II, proteins important for transcriptional elongation (Spt5, Spt16), or RNA processing (Sub2). Loss of Paf1 factors causes a reduction of Pol II Ser2 phosphorylation and shortened poly(A) tails, suggesting that the complex facilitates linkage of transcriptional and posttranscriptional events. Surprisingly, loss of Rtf1 or Cdc73, with little phenotypic consequence, results in loss of Paf1 factors from chromatin and a significant reduction in Paf1/Pol II association. Therefore, the major functions of Paf1 can be independent of actively transcribing Pol II.
Mueller
Cherie L
CL
Department of Biochemistry and Molecular Genetics, Molecular Biology Program, University of Colorado Health Science Center, B121, 4200 East Ninth Avenue, Denver, CO 80262, USA.
Porter
Stephanie E
SE
Hoffman
Matthew G
MG
Jaehning
Judith A
JA
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D005809:Genes, Regulator / Q000235:genetics*; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics; D009687:Nuclear Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D010766:Phosphorylation; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D035602:Transcriptional Elongation Factors / Q000235:genetics / Q000378:metabolism
D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D009687:Nuclear Proteins; C097698:PAF1 protein, S cerevisiae; D012333:RNA, Messenger; C071238:SPT16 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C069940:SPT5 transcriptional elongation factor; D012694:Serine; D012319:RNA Polymerase II; D000251:Adenosine Triphosphatases; C027900:RNA-dependent ATPase