The G1interval in the mammalian cell cycle: dual control by mass accumulation and stage-specific activities
- 1 March 1991
- journal article
- Published by Wiley in Cell Proliferation
- Vol. 24 (2), 215-228
- https://doi.org/10.1111/j.1365-2184.1991.tb01151.x
Abstract
The temporal determinants of the G1 cell cycle interval were investigated using nine mammalian cell lines. In each case, cells were allowed to proliferate for many cell cycles under conditions that slowed progress through S phase without an equivalent impairment of overall mass accumulation. This disproportionate inhibition of progress through the cell cycle caused newly produced cells to be more massive than usual. Under these growth conditions, the determinants of the length of the G1 interval became evident. For two cell lines, HeLa S3 and NIH 3T3, a protracted S phase, and the resultant increase in mass, resulted in a dramatically shortened G1 interval. Thus, for these cell lines, a major portion of G1 time exists to accommodate mass accumulation needed to initiate the subsequent S phase. Nevertheless, under conditions that protracted S phase and shortened the G1 interval, cells still exhibited a measurable G1 time, reflecting the stage-specific activities within G1. One activity that may be responsible for this obligatory G1 time is the synthesis of a labile protein. For other cells studied here, protraction of S phase also caused proliferating cells to become more massive, but in these cases there was no diminution of the G1 time. For these cells, the entire G1 interval must accommodate G1-specific activities necessary to initiate a new cell cycle. A unifying view of the G1 interval recognizes the two distinct influences that determine the time spent in G1: the need to accumulate sufficient mass to initiate a new DNA-division sequence; and the stage-specific events necessary for the subsequent S phase. The length of the G1 interval is dictated by the longer of these two time-consuming activities.Keywords
This publication has 39 references indexed in Scilit:
- Centriole ciliation and cell cycle variability during G1 phase of BALB/c 3T3 CellsJournal of Cellular Physiology, 1989
- An open mind?Nature, 1989
- The yang and yin of cell proliferation: An overviewJournal of Cellular Physiology, 1987
- Purification and characterization of two new high molecular weight forms of DNA polymerase .delta.Biochemistry, 1986
- Normal and perturbed Chinese hamster ovary cells: correlation of DNA, RNA, and protein content by flow cytometry.The Journal of cell biology, 1985
- DNA polymerase .delta.: one polypeptide, two activitiesBiochemistry, 1982
- The cell cycle and related concepts in cell proliferationThe Journal of Pathology, 1982
- Protein synthesis and the presence or absence of a measurable G1 in cultured chinese hamster cellsJournal of Cellular Physiology, 1980
- Hydroxyurea treatment affects the G1 phase in next generation CHO cellsExperimental Cell Research, 1977
- Temperature-sensitive mutants of Balb/3T3 cells: Description of a mutant affected in cellular and polyoma virus DNA synthesisCell, 1976