DP and E2F proteins: components of a heterodimeric transcription factor implicated in cell cycle control.

In mammalian cells, DRTF1/E2F is a transcription factor widely believed to integrate cell-cycle progression with the transcription apparatus through its cyclical interactions with important regulators of the cell cycle, such as the retinoblastoma tumour-suppressor gene product, cyclins and cyclin-dependent kinases. Recently, a number of exciting developments have uncovered the heterodimeric nature of DRTF1/E2F by defining two distinct families of proteins, DP and E2F, which comprise its activity; efficient DNA-binding activity arises when a DP protein interacts with an E2F protein. Combinatorial interactions generate a surprising array of sequence-specific heterodimers, a diversity that is probably necessary to enable different cell cycle regulating proteins to integrate their activities with transcription.