VprBP (HIV-1 Vpr-binding protein) is also known as DCAF1 (Ddb1- and Cul4-associated factor 1). VprBP was initially identified as a protein that co-immunoprecipitated with the HIV protein, viral protein R; however the physiological relevance of this association remains unclear. It has recently been shown that VprBP plays an essential role in cell cycle progression, and it associates with the DDB1-CUL4 E3 ligase complex.
