tsJT16, A Cell-cycle ts Mutant Defective in a Function Operating soon after Growth Stimulation, Failes to Induce a Primarily Activated Labile Nuclear Protein

[摘要] References(15)Cited-By(5)tsJT16 is a temperature-sensitive (ts) mutant of rat fibroblasts that has a ts defect in a function operating soon after the growth stimulation from the G0 phase. After the growth stimulation, the cells express several cell-cycle-dependent genes at both temperatures while they fail at the nonpermissive temperature to synthesize a protein p70 identified on two-dimensional gel electrophoresis. Here we report that 1) synthesis of p70 began within 1 h of stimulation, continued up to the 7th hour and then decreased; 2) the half-life of p70 was shortened after 6 h after the stimulation; 3) p70 was localized in the nuclear fraction; 4) p70 was likely to be a primarily induced protein; 5) mRNA of p70 was supposed to be synthesized exclusively within 2 h of growth stimulation. These and the previous results suggest that p70 is a nuclear protein responsible for the early stage of transition of cells from the G0 toward the S phase and is induced via a different signal transduction sequence from that for the c-fos gene.

[学科分类] 分子生物学，细胞生物学和基因

[关键词] cell cycle;G0-S transition;ts mutant;nuclear protein;signal transduction