E2Fregulated

E2Fregulated is a term used in molecular biology and genetics to describe genes or cellular processes that are controlled by transcription factors belonging to the E2F family. E2F proteins are a group of transcription factors that play a critical role in regulating the cell cycle, particularly in the transition from the G1 phase to the S phase, which is the period of DNA synthesis. They achieve this by binding to specific DNA sequences, known as E2F response elements, located in the promoter regions of target genes.

Genes regulated by E2F are typically involved in DNA replication, cell cycle progression, and apoptosis. This includes genes encoding for enzymes necessary for DNA synthesis, such as thymidine kinase and thymidylate synthase, as well as cyclins and cyclin-dependent kinases that drive cell cycle progression. The activity of E2F proteins is tightly controlled throughout the cell cycle, primarily by their interaction with retinoblastoma tumor suppressor protein (Rb). In the G1 phase, Rb binds to E2F, inhibiting its transcriptional activity and preventing the expression of its target genes. As the cell enters the S phase, Rb is phosphorylated by cyclin-CDK complexes, leading to its dissociation from E2F. Free E2F can then activate the transcription of genes required for DNA replication and cell division.

Dysregulation of E2F activity is a common feature of many cancers. Inactivation of Rb, for instance, due to mutations or viral oncoprotein binding, leads to uncontrolled E2F activity, driving excessive cell proliferation and tumor formation. Therefore, understanding E2F-regulated pathways is crucial for comprehending normal cell growth and development, as well as for developing therapeutic strategies against cancer.