REPAIRtoire - a database of DNA repair pathways

Welcome! Click here to login or here to register.
DNA damage
Draw a picture

Bujnicki Lab Homepage

"Human immunodeficiency virus type 1 Vpr-binding protein VprBP, a WD40 protein associated with the DDB1-CUL4 E3 ubiquitin ligase, is essential for DNA replication and embryonic development."

McCall CM, Miliani de Marval PL, Chastain PD 2nd, Jackson SC, He YJ, Kotake Y, Cook JG, Xiong Y

Published Sept. 1, 2008 in Mol Cell Biol volume 28 .

Pubmed ID: 18606781

Damaged DNA binding protein 1, DDB1, bridges an estimated 90 or more WD40 repeats (DDB1-binding WD40, or DWD proteins) to the CUL4-ROC1 catalytic core to constitute a potentially large number of E3 ligase complexes. Among these DWD proteins is the human immunodeficiency virus type 1 (HIV-1) Vpr-binding protein VprBP, whose cellular function has yet to be characterized but has recently been found to mediate Vpr-induced G(2) cell cycle arrest. We demonstrate here that VprBP binds stoichiometrically with DDB1 through its WD40 domain and through DDB1 to CUL4A, subunits of the COP9/signalsome, and DDA1. The steady-state level of VprBP remains constant during interphase and decreases during mitosis. VprBP binds to chromatin in a DDB1-independent and cell cycle-dependent manner, increasing from early S through G(2) before decreasing to undetectable levels in mitotic and G(1) cells. Silencing VprBP reduced the rate of DNA replication, blocked cells from progressing through the S phase, and inhibited proliferation. VprBP ablation in mice results in early embryonic lethality. Conditional deletion of the VprBP gene in mouse embryonic fibroblasts results in severely defective progression through S phase and subsequent apoptosis. Our studies identify a previously unknown function of VprBP in S-phase progression and suggest the possibility that HIV-1 Vpr may divert an ongoing chromosomal replication activity to facilitate viral replication.

This publication refers to following REPAIRtoire entries:


Last modification of this entry: Oct. 6, 2010

Add your own comment!

There is no comment yet.
Welcome stranger! Click here to login or here to register.
Valid HTML 4.01! This site is Emacs powered. Made with Django.