Can stimulate E2F-dependent transcription. Binds DNA cooperatively with E2F family members through the E2 recognition site, 5'-TTTC[CG]CGC-3', found in the promoter region of a number of genes whose products are involved in cell cycle regulation or in DNA replication (PubMed:8405995, PubMed:7739537). The E2F1:DP complex appears to mediate both cell proliferation and apoptosis. Blocks adipocyte differentiation by repressing CEBPA binding to its target gene promoters (PubMed:20176812). Component of the E2F:DP transcription factor complex. Forms heterodimers with E2F family members. The complex can interact with hypophosphorylated retinoblastoma protein RB1 and related proteins (RBL1 and RBL2) that inhibit the E2F transactivation domain. This repression involves recruitment of histone deacetylase (HDAC). During the cell cycle, from mid-to-late G1 phase, RB family members become phosphorylated, detach from the DRTF1/E2F complex to render E2F transcriptionally active. Viral oncoproteins, notably E1A, T-antigen and HPV E7, are capable of sequestering RB protein, thus releasing the active complex. Part of the E2F6.com-1 complex in G0 phase is composed of E2F6, MGA, MAX, TFDP1, CBX3, BAT8, EUHMTASE1, RING1, RNF2, MBLR, L3MBTL2 YAF2. Component of the DREAM complex (also named LINC complex) at least composed of E2F4, E2F5, LIN9, LIN37, LIN52, LIN54, MYBL1, MYBL2, RBL1, RBL2, RBBP4, TFDP1 and TFDP2. The complex exists in quiescent cells where it represses cell cycle-dependent genes. It dissociates in S phase when LIN9, LIN37, LIN52 and LIN54 form a subcomplex that binds to MYBL2. The complex TFDP1:E2F1 interacts with CEBPA; the interaction prevents CEBPA binding to target gene promoters and represses its transcriptional activity (PubMed:20176812). Shuttles between the cytoplasm and nucleus and translocates into the nuclear compartment upon heterodimerization with E2F1. Highest levels in muscle. Also expressed in brain, placenta, liver and kidney. Lower levels in lung and pancreas. Not detected in heart. Down-regulated during differentiation. Phosphorylation by E2F1-bound cyclin A-CDK2, in the S phase, inhibits E2F-mediated DNA binding and transactivation. Ubiquitinated by the BCR(KBTBD5) complex, leading to its subsequent degradation. E2F/DP transactivation can be mediated by several cofactors including TBP, TFIIH, MDM2 and CBP. Belongs to the E2F/DP family.