Synopses & Reviews
The E2F gene family of transcription factors is a regulator of the G1 to S phase transition of mammalian cell cycle.This volume details which cellular genes are thought to be regulated by E2F and describes models for E2F action based on protein-protein complexes that either positively or negatively influence cell growth. Also documented are the effects of altered E2F activity, achieved either by viral transformation or overexpression of E2F family members. Finally, a comparison is provided between E2F and cell cycle regulators from yeast, in the hopes that parallels can be drawn that will provide insight into G1/S phase specific transcription in mammalian cells. This volume synthesizes what is known about E2F and provides researchers with a solid foundation for future investigations.
It is of critical importance to maintain an appropriate balance between proliferation and quiescence or differentiation through- out the lifespan of all animals. An important control point in this balance occurs in the G, phase of the cell cycle. On the basis of environmental cues a cell in G, must decide whether to continue through the proliferative cycle and enter S phase (where DNA replication occurs) or to exit from the proliferative cycle into a nonreplicating state. Alterations in the mechanisms that nor- mally control this decision can lead to cancer, cell death, or loss of differentiated cellular phenotypes. The identification of the E2F gene family of transcription factors has allowed a more complete understanding of how the cell maintains an appropri- ate proliferative state. This volume provides an up-to-date ac- count of present reports concerning E2F as well as a framework for future investigations. E2F activity requires heterodimerization of two partners. Either partner can be one of several different transcription factors; E2Fl, E2F2, E2F3, E2F4, or E2F5 can heterodimerize with either DPl or DP2. Cellular promoters whose E2F sites mediate a link between transcription and proliferation drive genes whose products are required for DNA synthesis and genes that encode regulators of cell growth. A detailed analY$is of the role that E2F family members play in transcription from these promoters is presented in the chapter by J. E. SLANSKY and P. J. FARNHAM.