SYNTHESIS OF LOW-MOLECULAR WEIGHT RNA COMPONENTS A, C AND D BY POLYMERASE-II IN ALPHA-AMANITIN-RESISTANT HAMSTER CELLS

In an attempt to establish which RNA polymerase catalyzes the synthesis of the low molecular weight RNA components A, C and D, Ama 1 cells (mutant Chinese hamster cells) were used in experiments with addition of α-amanitin. Ama 1 cells contain an altered RNA polymerase II which is 800 times more resistant towards inhibition by α-amanitin than the wild type enzyme. Alpha-amanitin (up to 200 μg/ml) added to these cells does not affect the synthesis of the low molecular weight RNAs A, C and D. These data together with our previous data showing that α-amanitin (0.5 - 5.0 μg/ml) preferentially inhibits the synthesis of A, C and D in normal cells indicate that RNA polymerase II catalyzes the synthesis of the low molecular weight RNA components A, C and D. © 1979 Information Retrieval Limited.