Cell cycle control of gene expression in yeast.

Increasing evidence suggests that cell-cycle-regulated gene expression plays a crucial role in cell cycle control. In building yeast, as many as 250 genes (3-4% of all genes in this yeast) may be regulated in this way. One large group is expressed at the G1-S transition and includes cyclin genes, whose products control the p34(CDC28) protein kinase, as well as many genes essential for DNA synthesis. Two separate systems control the expression of these genes in the late G1 phase, but these systems have in common the SW16 protein, which may be a cell cycle stage-specific transcription factor.