title: Enhanced transcription by RNA polymerases II and III after inhibition of protein synthesis.
abstract: Intraperitoneal administration of cycloheximide (100 mg/kg) to rats produces a time-dependent rise in nuclear RNA polymerase II activity which is maximum at 30 min. This same concentration of cycloheximide also reduces RNA polymerase I activity to 64% of control within this time period. When 10 mg/kg of cycloheximide was administered, there was a 2-fold increase in both RNA polymerases II and III activities within 30 min as assayed in isolated nuclei. When these enzymes are solubilized from nuclei and resolved by DEAE-Sephadex, there is no significant change in the activity of RNA polymerase I or II when assayed on an exogenous template. It is suggested that the dual enhancement of nuclear RNA polymerase II and III activities is the result of a compensatory feedback relationship which exists between translation and transcription in vivo.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology*; D003513:Cycloheximide / Q000494:pharmacology*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D005260:Female; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D012319:RNA Polymerase II / Q000378:metabolism*; D012320:RNA Polymerase III / Q000378:metabolism*; D051381:Rats; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D003513:Cycloheximide; D012319:RNA Polymerase II; D012321:DNA-Directed RNA Polymerases; D012320:RNA Polymerase III