Overexpression of human cyclin a advances entry into S phase
Rosenberg, A.R.; Zindy, F.; Le Deist, F.; Mouly, H.; Métézeau, P.; Bréchot, C.; Lamas, E.
Oncogene 10(8): 1501-1509
1995
ISSN/ISBN: 0950-9232 PMID: 7731704 Document Number: 448018
Cyclin A is a cell cycle regulatory protein that functions in mitotic and S-phase control in mammalian cells. Using a genomic construction corresponding to the human cyclin A gene under the control of its own promoter, we have established stable transfectants overexpressing cyclin A protein. Experiments assisted by laser scanning image cytometry showed that this overexpression begins from late G1 phase onwards and is therefore cell cycle-regulated in this model. We demonstrated that this overexpression advances entry into S phase, leading to a contraction of the overall cell generation time. These results provide evidence that cyclin A can be a rate-limiting factor with respect to the control of the transition to S phase in mammalian cells.