title: Kinase Cak1 functionally interacts with the PAF1 complex and phosphatase Ssu72 via kinases Ctk1 and Bur1.
abstract: Protein kinases orthologous with Cak1 of Saccharomyces cerevisiae (ScCak1) appear specific to ascomycetes. ScCak1 phosphorylates Cdc28, the cyclin-dependent kinase (CDK) governing the cell cycle, as well as Kin28, Bur1 and Ctk1, CDKs required for the transcription process performed by RNA polymerase II (RNA Pol II). Using genetic methods, we found that Cak1 genetically interacts with Paf1 and Ctr9, two components belonging to the PAF1 elongation complex needed for histone modifications, and with Ssu72, a protein phosphatase that dephosphorylates serine-5 phosphate in the RNA Pol II C-terminal domain. We present evidence suggesting that the interactions linking Cak1 with the PAF1 complex and with Ssu72 are not direct but mediated via Ctk1 and Bur1. We discuss the possibility that Ssu72 intervenes at the capping checkpoint step of the transcription cycle.
authors.affiliation: Institut Curie, UMR2027 CNRS, Centre Universitaire, Orsay, France.
authors.forename: Carine
authors.initials: C
authors.lastname: Ganem
authors.forename: Chaouki
authors.initials: C
authors.lastname: Miled
authors.forename: Céline
authors.initials: C
authors.lastname: Facca
authors.forename: Jean-Gabriel
authors.initials: JG
authors.lastname: Valay
authors.forename: Gilles
authors.initials: G
authors.lastname: Labesse
authors.forename: Samia
authors.initials: S
authors.lastname: Ben Hassine
authors.forename: Carl
authors.initials: C
authors.lastname: Mann
authors.forename: Gérard
authors.initials: G
authors.lastname: Faye
mesh_terms: D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D005800:Genes, Fungal; D005804:Genes, Lethal; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases; D010957:Plasmids / Q000235:genetics; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013489:Suppression, Genetic; D013696:Temperature; D035602:Transcriptional Elongation Factors; D039221:mRNA Cleavage and Polyadenylation Factors; D000095043:Cyclin-Dependent Kinase-Activating Kinase
chemical_list: C118305:CTDK-I protein complex, S cerevisiae; C104718:CTR9 protein, S cerevisiae; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D004271:DNA, Fungal; D009687:Nuclear Proteins; C097698:PAF1 protein, S cerevisiae; C416934:SSU72 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D035602:Transcriptional Elongation Factors; D039221:mRNA Cleavage and Polyadenylation Factors; D011494:Protein Kinases; D018844:Cyclin-Dependent Kinases; C414163:SGV1 protein, S cerevisiae; D010749:Phosphoprotein Phosphatases; D000095043:Cyclin-Dependent Kinase-Activating Kinase