title: 5,6-Dichloro-1-beta-D-ribofuranosylbenzimidazole inhibits a HeLa protein kinase that phosphorylates an RNA polymerase II-derived peptide.
abstract: A protein kinase that phosphorylates Lys(Tyr-Ser-Pro-Thr-Ser-Pro-Ser)4, a synthetic peptide homologous to the evolutionarily-conserved, tandemly-repeated heptapeptide sequence at the C-terminus of the large subunit of eukaryotic RNA polymerase II, has been detected in HeLa cell extracts and chromatographic fractions therefrom. The enzyme, which phosphorylates serine principally, can be distinguished from previously described major protein kinases which phosphorylate the peptide poorly, if at all. It is inhibited by the nucleoside analog, 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole. Results suggest that human placental RNA polymerase II is phosphorylated at the C-terminus of the large subunit by the partially-purified protein kinase and that the phosphorylation is also sensitive to the nucleoside analog.
authors.affiliation: Biology Division, Oak Ridge National Laboratory, TN 37831-8077.
authors.forename: A
authors.initials: A
authors.lastname: Stevens
authors.forename: M K
authors.initials: MK
authors.lastname: Maupin
mesh_terms: D000595:Amino Acid Sequence; D047388:Casein Kinases; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology*; D006367:HeLa Cells / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000378:metabolism*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism; D012319:RNA Polymerase II / Q000378:metabolism*; D012263:Ribonucleosides / Q000494:pharmacology*; D013379:Substrate Specificity
chemical_list: D009842:Oligopeptides; D047428:Protein Kinase Inhibitors; D012263:Ribonucleosides; D004004:Dichlororibofuranosylbenzimidazole; D011494:Protein Kinases; D047388:Casein Kinases; D012319:RNA Polymerase II