PMID: 6412755Oct 13, 1983Paper

Effects of temperature changes on thymidine kinase in heat- and cold-sensitive cell-cycle mutants and 'wild-type' murine P-815 cells

Biochimica Et Biophysica Acta
E SchneiderR Schindler

Abstract

Two heat-sensitive (arrested in G1 at 39.5 degrees C) and two cold-sensitive (arrested in G1 at 33 degrees C) clonal cell-cycle mutants that had been isolated from the same clone (K 21), of the murine mastocytoma P-815 cell line, were tested for thymidine kinase (EC 2.7.1.21) activity. After shift of mutant cells to the nonpermissive temperature, thymidine kinase activity decreased, and minimal levels (i.e., less than 3% of those observed for 'wild-type' K 21 cells at the respective temperature) were attained within 16 h in heat-sensitive and after 3-4 days in cold-sensitive mutants, which is in good agreement with kinetics of accumulation of heat-sensitive and cold-sensitive cells in G1 phase. After return of arrested mutant cells to the permissive temperature, thymidine kinase of heat-sensitive cells increased rapidly and in parallel with entry of cells into the S phase. In cultures of cold-sensitive cells, however, initiation of DNA synthesis preceded the increase of thymidine kinase activity by approx. one cell-cycle time. Thymidine kinase activities in revertants of the heat-sensitive and cold-sensitive mutants were similar to those of 'wild-type' cells. In 'wild-type' K 21 cells incubated at 39.5 degrees C, thymidine kina...Continue Reading

References

Jun 1, 1960·Biochemical Pharmacology·J P GREEN, M DAY

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Citations

Jul 1, 1985·Proceedings of the National Academy of Sciences of the United States of America·B LüscherD Schümperli
Aug 1, 1985·Journal of Cellular Physiology·D L Coppock, A B Pardee
Sep 21, 1989·Biochimica Et Biophysica Acta·J C SchaerR Schindler

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