A novel RNA polymerase II C-terminal domain phosphatase that preferentially dephosphorylates serine 5.
The transcription and processing of pre-mRNA in eukaryotic cells are regulated in part by reversible phosphorylation of the C-terminal domain of the largest RNA polymerase (RNAP) II subunit. The CTD phosphatase, FCP1, catalyzes the dephosphorylation of RNAP II and is thought to play a major role in polymerase recycling. This study describes a family of small CTD phosphatases (SCPs) that preferentially catalyze the dephosphorylation of Ser5 within the consensus repeat. The preferred substrate for SCP1 is RNAP II phosphorylated by TFIIH. Like FCP1, the activity of SCP1 is enhanced by the RAP74 subunit of TFIIF. Expression of SCP1 inhibits activated transcription from a number of promoters, whereas a phosphatase-inactive mutant of SCP1 enhances transcription. Accordingly, SCP1 may play a role in the regulation of gene expression, possibly by controlling the transition from initiation/capping to processive transcript elongation.
Department of Medicine, University of California San Diego, La Jolla, California 92093-0650, USA.
Michele
M
Yeo
Patrick S
PS
Lin
Michael E
ME
Dahmus
Gordon N
GN
Gill
D000595:Amino Acid Sequence; D020134:Catalytic Domain; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins; D010455:Peptides / Q000737:chemistry; D010749:Phosphoprotein Phosphatases / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry*; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000737:chemistry*; D013379:Substrate Specificity; D014158:Transcription, Genetic; D014162:Transfection
D018076:DNA, Complementary; D009687:Nuclear Proteins; D010455:Peptides; D020033:Protein Isoforms; D012694:Serine; D005982:Glutathione Transferase; D012319:RNA Polymerase II; C413483:CTDSP1 protein, human; D010749:Phosphoprotein Phosphatases; C116022:carboxy-terminal domain phosphatase; D010744:Phosphoric Monoester Hydrolases