The last CTD repeat of the mammalian RNA polymerase II large subunit is important for its stability.
The phosphorylation of the RNA polymerase II (Pol II) C-terminal domain (CTD) has been shown to affect the initiation, and transition to elongation of the Pol II complex. The differential phosphorylation of serines within this domain coincides with the recruitment of factors important for pre-mRNA processing and transcriptional elongation. A role for tyrosine and threonine phosphorylation has yet to be described. The discovery of kinases that express a preference for specific residues within this sequence suggests a mechanism for the controlled recruitment and displacement of CTD-interacting partners during the transcription cycle. The last CTD repeat (CTD52) contains unique interaction sites for the only known CTD tyrosine kinases, Abl1/c-Abl and Abl2/Arg, and the serine/threonine kinase casein kinase II (CKII). Here, we show that removal or severe disruption of the last CTD repeat, but not point mutation of its CKII sites, results in its proteolytic degradation to the Pol IIb form in vivo, but does not appear to affect the specific transcription of genes. These results suggest a possible mechanism of transcription control through the proteolytic removal of the Pol II CTD.
Chapman
Rob D
RD
Institute of Clinical Molecular Biology and Tumour Genetics, GSF Research Center for Environment and Health, Marchioninistr. 25, D-81377 Munich, Germany.
Palancade
Benoit
B
Lang
Andreas
A
Bensaude
Olivier
O
Eick
Dirk
D
D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D002470:Cell Survival; D004795:Enzyme Stability; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D017354:Point Mutation / Q000235:genetics; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012319:RNA Polymerase II / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020449:Repetitive Sequences, Amino Acid; D017384:Sequence Deletion / Q000235:genetics; D014158:Transcription, Genetic
D010446:Peptide Fragments; D021122:Protein Subunits; D012319:RNA Polymerase II