A carboxyl-terminal-domain kinase associated with RNA polymerase II transcription factor delta from rat liver.
We previously purified RNA polymerase II transcription factor delta from rat liver and found that it has an associated DNA-dependent ATPase (dATPase) activity. In this report, we show that delta is also closely associated with a protein kinase activity that catalyzes phosphorylation of the largest subunit of RNA polymerase II. Kinase activity copurifies with transcription and DNA-dependent ATPase (dATPase) activities when delta is analyzed by anion- and cation-exchange HPLC as well as by sucrose gradient sedimentation, arguing that delta possesses all three activities. Phosphorylation of the largest subunits of both rat and yeast RNA polymerase II is stimulated by DNA, whereas phosphorylation of a synthetic peptide containing multiple copies of the carboxyl-terminal heptapeptide repeat is not. Although both ATP and GTP appear to function as phosphate donors, GTP is utilized less than 10% as well as ATP. These findings suggest that delta may exert its action in transcription at least in part through a mechanism involving phosphorylation of the largest subunit of RNA polymerase II.
Serizawa
H
H
Program in Molecular and Cell Biology, Oklahoma Medical Research Foundation, Oklahoma City 73104.
Conaway
R C
RC
Conaway
J W
JW
D000251:Adenosine Triphosphatases / Q000302:isolation & purification / Q000378:metabolism; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004265:DNA Helicases; D004268:DNA-Binding Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D050981:Erythroid-Specific DNA-Binding Factors; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D046911:Macromolecular Substances; D008970:Molecular Weight; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D012319:RNA Polymerase II / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism*
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D046911:Macromolecular Substances; D014157:Transcription Factors; D011494:Protein Kinases; D012319:RNA Polymerase II; D000251:Adenosine Triphosphatases; D004265:DNA Helicases