title: Genetic interactions of Spt4-Spt5 and TFIIS with the RNA polymerase II CTD and CTD modifying enzymes in Saccharomyces cerevisiae.
abstract: Genetic and biochemical studies have identified many factors thought to be important for transcription elongation. We investigated relationships between three classes of these factors: (1) transcription elongation factors Spt4-Spt5, TFIIS, and Spt16; (2) the C-terminal heptapeptide repeat domain (CTD) of RNA polymerase II; and (3) protein kinases that phosphorylate the CTD and a phosphatase that dephosphorylates it. We observe that spt4 and spt5 mutations cause strong synthetic phenotypes in combination with mutations that shorten or alter the composition of the CTD; affect the Kin28, Bur1, or Ctk1 CTD kinases; and affect the CTD phosphatase Fcp1. We show that Spt5 co-immunoprecipitates with RNA polymerase II that has either a hyper- or a hypophosphorylated CTD. Furthermore, mutation of the CTD or of CTD modifying enzymes does not affect the ability of Spt5 to bind RNA polymerase II. We find a similar set of genetic interactions between the CTD, CTD modifying enzymes, and TFIIS. In contrast, an spt16 mutation did not show these interactions. These results suggest that the CTD plays a key role in modulating elongation in vivo and that at least a subset of elongation factors are dependent upon the CTD for their normal function.
authors.affiliation: Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, 95064, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Lindstrom
authors.forename: G A
authors.initials: GA
authors.lastname: Hartzog
mesh_terms: D015153:Blotting, Western; D002868:Chromosomal Proteins, Non-Histone; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D005800:Genes, Fungal; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D011233:Precipitin Tests; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D012694:Serine / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D035165:Transcription Factors, General; D035602:Transcriptional Elongation Factors
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D005656:Fungal Proteins; D009687:Nuclear Proteins; C080991:SPT4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D035165:Transcription Factors, General; D035602:Transcriptional Elongation Factors; C018648:transcription factor S-II; C069940:SPT5 transcriptional elongation factor; D012694:Serine; D011494:Protein Kinases; C060137:carboxy-terminal domain kinase; D012319:RNA Polymerase II