Kinase Cak1 functionally interacts with the PAF1 complex and phosphatase Ssu72 via kinases Ctk1 and Bur1

Mol Genet Genomics. 2006 Feb;275(2):136-47. doi: 10.1007/s00438-005-0071-y. Epub 2005 Dec 1.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cyclin-Dependent Kinase-Activating Kinase
  • Cyclin-Dependent Kinases / genetics
  • Cyclin-Dependent Kinases / metabolism*
  • DNA, Complementary / genetics
  • DNA, Fungal / genetics
  • Genes, Fungal
  • Genes, Lethal
  • Mutation
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Phosphoprotein Phosphatases
  • Plasmids / genetics
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Suppression, Genetic
  • Temperature
  • Transcriptional Elongation Factors
  • mRNA Cleavage and Polyadenylation Factors

Substances

  • CTDK-I protein complex, S cerevisiae
  • CTR9 protein, S cerevisiae
  • Carrier Proteins
  • Cell Cycle Proteins
  • DNA, Complementary
  • DNA, Fungal
  • Nuclear Proteins
  • PAF1 protein, S cerevisiae
  • SSU72 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcriptional Elongation Factors
  • mRNA Cleavage and Polyadenylation Factors
  • Protein Kinases
  • Cyclin-Dependent Kinases
  • SGV1 protein, S cerevisiae
  • Phosphoprotein Phosphatases
  • Cyclin-Dependent Kinase-Activating Kinase