DP forms a heterodimer with E2F and regulates genes involved in cell cycle progression. The transcriptional activity of E2F is inhibited by the retinoblastoma protein which binds to the E2F-DP heterodimer [2] and negatively regulates the G1-S transition.

1: In vivo association of E2F and DP family proteins. Wu CL, Zukerberg LR, Ngwu C, Harlow E, Lees JA; Mol Cell Biol. 1995;15:2536-2546. PMID:7739537

2: Structure of the Rb C-terminal domain bound to E2F1-DP1: a mechanism for phosphorylation-induced E2F release. Rubin SM, Gall AL, Zheng N, Pavletich NP; Cell. 2005;123:1093-1106. PMID:16360038