title: DNA-dependent RNA polymerase activities in hepatopancreas nuclei from Mytilus galloprovincialis Lamarck.
abstract: It has been shown that RNA synthesis in isolated hepatopancreas nuclei from Mytilus galloprovincialis is catalyzed by three DNA-dependent RNA polymerases (I, II and III) which resemble those identified in nuclei from mammalian cells. RNA polymerase I is active at 50 mM (NH4)2SO4, catalyzes the synthesis of GMP-rich ribosomal-like RNA and is completely resistant to the toadstool toxin alpha-amanitin. RNA polymerase II and III are active at higher (NH4)2SO4 concentrations, catalyze the synthesis of DNA-like RNA and are inhibited by very low (0.5-1 microgram/ml) and high (200 microgram/ml) concentrations of alpha-amanitin, respectively. Hepatopancreas nuclei retain considerable RNAase activity. Nuclear RNA polymerase activity may be underestimated since a part of the synthetized RNA is degraded.
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000201:enzymology*; D012321:DNA-Directed RNA Polymerases / Q000032:analysis*; D004064:Digestive System / Q000201:enzymology*
chemical_list: D012321:DNA-Directed RNA Polymerases