Protein kinases from Aspergillus nidulans that phosphorylate the carboxyl-terminal domain of the largest subunit of RNA polymerase II.
Three serine kinases which phosphorylate the CTD of RNA polymerase II have been identified in Aspergillus nidulans. The kinases (KI, KII, KIII) were identified using a synthetic peptide containing four copies of the CTD consensus heptamer repeat, and differ in chromatographic behavior, and apparent molecular mass (KI approximately 60kDa; KII approximately 82kDa; KIII approximately 43 kDa). KIII utilized, in addition to peptide, histone H1 as substrate, whereas casein was not phosphorylated by any of the three kinases. The kinases appear to be unrelated to the p34cdc2 kinase, as judged by Western blot analysis and the position of serine phosphorylation of the synthetic CTD peptide. KI was highly purified and renaturation experiments have shown that it consists of a single polypeptide of 57 kDa. KI also phosphorylated RNA polymerase II associated in a preinitiation complex.
Stone
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Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854-5635.
Reinberg
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D
D000595:Amino Acid Sequence; D001233:Aspergillus nidulans / Q000201:enzymology*; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010748:Phosphopeptides / Q000302:isolation & purification; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism*; D012265:Ribonucleotides / Q000378:metabolism; D013379:Substrate Specificity
D007527:Isoenzymes; D046911:Macromolecular Substances; D010748:Phosphopeptides; D012265:Ribonucleotides; D011494:Protein Kinases; D012319:RNA Polymerase II