Phosphorylation of S-II is not affected by inhibitors of RNA synthesis.
S-II is an essential factor for RNA polymerase II-mediated transcription. A phosphorylated form of S-II, termed S-II has been shown to be present in cells at half the concentration of S-II. In studies on the role of phosphorylation and dephosphorylation of S-II in transcription, the possibility that phosphorylation of S-II is coupled with transcription in vivo was investigated. The phosphorylation of S-II was measured in mouse L cells cultured with two typical inhibitors of RNA synthesis. Neither of these inhibitors, 5, 6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) and actinomycin D, affected the phosphorylation of S-II under conditions where 75 to 98% of RNA synthesis was inhibited at the initiation and elongation step, respectively. These results indicate that the phosphorylation of S-II and transcription are independent processes.
S
S
Hirashima
Y
Y
Nakanishi
K
K
Sekimizu
S
S
Natori
D000818:Animals; D003609:Dactinomycin / Q000494:pharmacology; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology; D007163:Immunosorbent Techniques; D007739:L Cells / Q000378:metabolism; D051379:Mice; D009363:Neoplasm Proteins / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D012313:RNA / Q000096:biosynthesis*; D035165:Transcription Factors, General; D014158:Transcription, Genetic / Q000187:drug effects; D035602:Transcriptional Elongation Factors; D014529:Uridine / Q000378:metabolism
D009363:Neoplasm Proteins; D010710:Phosphates; D010750:Phosphoproteins; D035165:Transcription Factors, General; D035602:Transcriptional Elongation Factors; C018648:transcription factor S-II; D003609:Dactinomycin; D004004:Dichlororibofuranosylbenzimidazole; D012313:RNA; D014529:Uridine