Simian virus 40 large T-antigen expression decreases the G1 and increases the G2 + M cell cycle phase durations in exponentially growing cells.
The effect of simian virus 40 large T-antigen (Tag) expression on the cell cycle of exponentially growing, established, mouse NIH 3T3 fibroblasts was examined by using a sensitive flow cytometric assay to analyze nonselected cells immediately after infection with a Tag-encoding recombinant retrovirus. Tag expression resulted in reduced percentages of G1-phase cells and increased percentages of S- and G2 + M-phase cells compared with cell populations infected with a control virus not encoding the Tag gene. Cell cycle-blocking drugs were used to examine the exit rate for each of the cell cycle phases, G1, S, and G2 + M, for Tag-expressing and Tag-nonexpressing cells growing in the same cell culture dish. As a result of Tag expression, the duration of the G1 phase was decreased (average G1-phase exit duration decreased by 18%) and the duration of the G2 + M phase was increased (average G2 + M exit duration increased by 29%). The duration of S phase was unaffected by Tag expression.
Sladek
T L
TL
Department of Genetics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106.
Jacobberger
J W
JW
D016475:3T3 Cells; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division; D016193:G1 Phase; D016195:G2 Phase; D006378:Helper Viruses / Q000235:genetics / Q000502:physiology; D007700:Kinetics; D051379:Mice; D008938:Mitosis; D015739:Nocodazole / Q000494:pharmacology; D013539:Simian virus 40 / Q000235:genetics / Q000502:physiology*; D014779:Virus Replication
D000952:Antigens, Polyomavirus Transforming; D015739:Nocodazole