Bur1/Bur2 and the Ctk complex in yeast: the split personality of mammalian P-TEFb.
Eukaryotic organisms possess a host of factors that regulate transcriptional elongation. In higher eukaryotes, the transcription factor P-TEFb not only regulates phosphorylation of the RNA polymerase II C-terminal domain, but it also inhibits the action of transcriptional repressors and is required for the association of several elongation factors with the transcribing polymerase. In the yeast Saccharomyces cerevisiae, the cyclin dependent kinases Bur1/Bur2 and Ctk complex (Ctk1, 2 and 3) are also able to impact several aspects of transcription. Together, these two kinase complexes appear to functionally reconstitute the activity of P-TEFb in yeast. Recent findings regarding the role of these kinases in histone tail modifications and transcriptional regulation is briefly reviewed below.
Wood
Adam
A
Department of Biochemistry, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA.
Shilatifard
Ali
A
D000818:Animals; D018844:Cyclin-Dependent Kinases / Q000378:metabolism*; D016213:Cyclins / Q000378:metabolism*; D006801:Humans; D010766:Phosphorylation; D042925:Positive Transcriptional Elongation Factor B / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D014158:Transcription, Genetic
C414164:Bur2 protein, S cerevisiae; C118305:CTDK-I protein complex, S cerevisiae; D016213:Cyclins; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; D042925:Positive Transcriptional Elongation Factor B; D018844:Cyclin-Dependent Kinases; C414163:SGV1 protein, S cerevisiae; D012319:RNA Polymerase II