Evidence that the time of entry into S is determined by events occurring in early G1.

摘要: The length of the prereplicative period after stimulation quiescent WI-38 cells is prolonged in proportion to time are incubated prior serum addition. Previous results from this laboratory have shown that prolongation does not result a delay induction events which occur during G0/G1 transition (i.e. c-fos or c-myc expression) (Owen, T., Cosenza, S., Soprano, D. R., and K. J. (1987) Biol. Chem. 262 15111-15117). It was goal present studies examine expression other growth-associated genes known be induced maximally accumulate later G1 identify whose coupled entry into S rather than mitogenic stimulation. In order do this, temporal pattern variety (thymidine kinase, p53, 2A9/calcyclin, ornithine decarboxylase, 4F1/vimentin, c-Ha-ras) studied stimulated either 12 days 26 plating. We report maximum accumulation each these transcripts, with exception c-Ha-ras, delayed 26-day cell group for 10 h, approximately equal S. Thus particular would appear closely sequence These suggest located early G1, following leading but such as decarboxylase 4F1/vimentin. addition, provide molecular evidence definitive programmed gene progression out G0 through