PEST regions, proteolysis and cell cycle progression.

How eucaryotic cells control cell division is both a major intellectual challenge and a problem of considerable medical importance. A decade of studies on oncogenes has made it abundantly clear that protein kinases play a central role in regulating mitosis. In this essay, I review a number of recent discoveries providing evidence that selective proteolysis, like phosphorylation, is an important mechanism for ordering metabolic events within the cell cycle.