Human mutant cell lines with altered RNA polymerase II.
A human fibrosarcoma cell line, HT-1080-6TG-9AM, resistant to alpha-amanitin at concentrations up to 10 micrograms/ml, was isolated after ethylmethanesulfonate mutagenesis and stepwise selection. The mutation is stable and dominant. RNA polymerase II purified from the mutant cells showed an altered affinity for labeled alpha-amanitin and the sensitivity of the enzyme to the fungal toxin was decreased 50- to 100-fold. This functional test demonstrated that the biochemical basis for the resistance of the cells to alpha-amanitin is due to an alteration of RNA polymerase II.
D000546:Amanitins / Q000378:metabolism / Q000494:pharmacology*; D002460:Cell Line; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D005354:Fibrosarcoma; D006801:Humans; D009154:Mutation; D012319:RNA Polymerase II / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
D000546:Amanitins; D012319:RNA Polymerase II; D012321:DNA-Directed RNA Polymerases