The morphogenesis checkpoint: how yeast cells watch their figures

The morphogenesis checkpoint maintains coordination between the process of bud formation and the nuclear events of the cell cycle in yeast. This checkpoint regulates the Wee1 homolog, Swe1p, to induce cell-cycle delay or arrest when aspects of bud formation are defective. A variety of studies have suggested that this checkpoint can monitor actin organization, septin organization, the presence of a bud and even the size of a bud. The evidence for these proposals is reviewed, highlighting recent findings indicating that Swe1p degradation is controlled by the cell shape change that accompanies bud emergence.