R&D Systems offers products for members of the E2F/DP family of transcription factors. E2F-1 (adenovirus E2 gene promoter region binding factor 1; also retinoblastoma [RB]-binding protein 3/RBP3) is a 57 - 60 kDa nuclear member of the E2F/DP family of transcription factors. It has a dual function, mediating both cell proliferation and apoptosis in a context-dependent manner. Human E2F-1 is 437 amino acids (aa) in length. It contains a cyclin A: CDK2 binding site (aa 67 - 108), a DNA-binding region (aa 110 - 194), and an RB protein binding motif (aa 409 - 426) that, when engaged, inactivates E2F-1.
E2F-2 (viral E2-associated factor 2) is a 50 - 55 kDa protein which is principally expressed by placenta, and forms a DNA-activating E2F heterodimeric complex with DP-1 or -2. This complex, when active, promotes cell cycle progression. In quiescent cells, association of E2F-2 with the retinoblastoma-tumor suppressor gene product termed pRB suppresses its activity.
E2F-4 (viral E2-associated factor 4) is a 50 kDa protein which is ubiquitously and constitutively expressed, and forms a DNA-binding E2F heterodimeric complex with DP-1. This complex, when associated with p130/RBL2 and a series of LIN-numbered proteins, represses cell cycle-dependent genes during G0 and G1.