The Proliferation-Quiescence Decision Is Controlled by a Bifurcation in CDK2 Activity at Mitotic Exit (Cell 2013)
°Õ¾±²õ²õ³Ü±ðÌýÌýin metazoans is regulated by transitions of cells between quiescence and proliferation. The hallmark of proliferating populations is progression through the cell cycle, which is driven byÌýÌý(CDK) activity. Here, we introduce a live-cell sensor for CDK2 activity and unexpectedly found thatÌýÌýbifurcate into two populations as they exit mitosis. Many cells immediately commit to the next cell cycle by building up CDK2 activity from an intermediate level, while other cells lack CDK2 activity and enter a transient state of quiescence. This bifurcation is directly controlled by theÌýÌýÌýand is regulated byÌýÌýduring a restriction window at the endÌýof the previous cell cycle. Thus, cells decide at the end of mitosis to either start the next cell cycle by immediately building up CDK2 activity or to enter a transient G0-like state by suppressing CDK2 activity.