DRTF1/E2F: A Molecular Switch in Cell Cycle Control

The cell cycle is a series of phases through which a cell must pass in order to divide. It is usually considered to be composed of four phases: the gap before DNA replication (G1), the DNA synthesis phase (S), the gap after DNA replication (G2) and the mitotic phase (M). In fact these phases represent a series of complex events which are regulated at different levels. One important level of control is the regulation of the transcriptional activity of particular genes during the cell cycle.