Cyclins, Cdks, and Cyclin Kinase Inhibitors
This extract was created in the absence of an abstract.
Excerpt
After each mitotic cycle, a cell either remains in the cell cycle and divides once again, or withdraws from the cell cycle and adopts an alternative, nonproliferating cell fate (e.g., quiescence or terminal differentiation). This “decision,” first called Start by Lee Hartwell and coworkers, was discovered and initially characterized by genetic analyses of the cell cycle of the yeast, Saccharomyces cerevisiae (Hartwell et al. 1974). Upon completion of Start, yeast become committed to complete the mitotic cycle and simultaneously initiate the parallel pathways leading to spindle pole body duplication, bud emergence, and DNA replication. An analogous set of events is thought to take place during the G1 phase of the mammalian cell cycle (Zetterberg and Larson 1985), and this is often called the restriction point (Pardee 1974). Prior to the restriction point, but not after, the cell exits the cell cycle if specific mitogenic and growth signals are absent.
Cells...
