In our attempts to characterize a temperature-sensitive mutant (ts-2) of monkey kidney cell line BSC-1, we have provided evidence to show that the mutant was defective in the synthesis or processing of rRNA (45, 28 and 18 s) molecules at 39·5°C and there was indication that the nucleolar RNA polymerase (I) or some factor associated with its functional activity was thermolabile at the restricted temperature of 39·5°C. The enzyme in the wild type cell line was, however, stable at this temperature. Though conclusive evidence to implicate RNA polymerase (I) was not obtained in these experiments, temperature-sensitivity tests with crude enzyme extracts of the RNA polymerase in ts-2 showed that it contained a temperature-sensitive factor which was either degraded rapidly or failed to be eluted out of the DEAE-Sephadex column. This temperature-sensitive factor was not affected by α-amanitin.
JOURNAL ARTICLE| 01 May 1973
Temperature-Sensitive RNA Polymerase of a Mammalian Cell Mutant
P. M. NAHA
National Institute for Medical Research, Mill Hill, London, N.W.7, England
Received: 12 Sep 1972
Online Issn: 1477-9137
Print Issn: 0021-9533
Copyright © 1973 The Company of Biologists Ltd.
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P. M. NAHA; Temperature-Sensitive RNA Polymerase of a Mammalian Cell Mutant. J Cell Sci 1 May 1973; 12 (3): 839–845. doi: https://doi.org/10.1242/jcs.12.3.839
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