Ubiquitin-mediated processes orchestrate critical DNA-damage signaling and repair pathways. We identify human DVC1 (C1orf124; Spartan) as a cell cycle-regulated anaphase-promoting complex (APC) substrate that accumulates at stalled replication forks. DVC1 recruitment to sites of replication stress requires its ubiquitin-binding UBZ domain and PCNA-binding PIP box motif but is independent of RAD18-mediated PCNA monoubiquitylation. Via a conserved SHP box, DVC1 recruits the ubiquitin-selective chaperone p97 to blocked replication forks, which may facilitate p97-dependent removal of translesion synthesis (TLS) DNA polymerase η (Pol η) from monoubiquitylated PCNA. DVC1 knockdown enhances UV light-induced mutagenesis, and depletion of human DVC1 or the Caenorhabditis elegans ortholog DVC-1 causes hypersensitivity to replication stress-inducing agents. Our findings establish DVC1 as a DNA damage-targeting p97 adaptor that protects cells from deleterious consequences of replication blocks and suggest an important role of p97 in ubiquitin-dependent regulation of TLS.
Nature Structural and Molecular Biology, 2012, Vol 19, Issue 11, p. 1084-92
Adenosine Triphosphatases; Anaphase-Promoting Complex-Cyclosome; Animals; Caenorhabditis elegans; Cell Cycle Proteins; DNA Damage; DNA Replication; DNA-Binding Proteins; DNA-Directed DNA Polymerase; Flow Cytometry; Gene Knockdown Techniques; Green Fluorescent Proteins; Humans; Immunoblotting; Immunoprecipitation; Mass Spectrometry; Mutagenesis; Plasmids; Proliferating Cell Nuclear Antigen; RNA Interference; RNA, Small Interfering; Signal Transduction; Ubiquitin; Ubiquitin-Protein Ligase Complexes