title: Transcriptional capacity of rat liver nuclei and of isolated chromatin at different ammonium sulphate concentrations.
abstract: The transcription of freshly prepared nuclei and lysates from rat liver is stimulated by exogenous RNA polymerase B from calf thymus to an insignificant extent only. This also holds for chromatin isolated from nuclei lysates by separation on a Sepharose 4 B column. After removal of histone H1 by pretreatment with 0.2 M ammonium sulphate no further stimulation by added RNA polymerase has been found. If, however, the incubation time was extended, or the nuclei had been kept frozen at -20 degrees C for some time before use, a significant increase in RNA synthesis by the added RNA polymerase was obtained. In the freshly prepared nuclei as well as in the undamaged chromatin the template capacity was highly restricted. This can be seen from the fact that after pretreatment of the chromatin with 0.4 M ammonium sulphate the RNA synthesis was stimulated about 13fold.
mesh_terms: D000645:Ammonium Sulfate / Q000494:pharmacology*; D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D002843:Chromatin / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000494:pharmacology; D051381:Rats; D013698:Templates, Genetic; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D002843:Chromatin; D011092:Polyethylene Glycols; D000645:Ammonium Sulfate