MCM8IP activates the MCM8-9 helicase to promote DNA synthesis and homologous recombination upon DNA damage

ABSTRACT: Homologous recombination (HR) mediates the error-free repair of DNA double-strand breaks to maintain genomic stability. Here we characterize C17orf53/MCM8IP, an OB-fold containing protein that binds ssDNA, as a DNA repair factor involved in HR. MCM8IP-deficient cells exhibit HR defects, especially in long-tract gene conversion, occurring downstream of RAD51 loading, consistent with a role for MCM8IP in HR-dependent DNA synthesis. Moreover, loss of MCM8IP confers cellular sensitivity to crosslinking agents and PARP inhibition. Importantly, we report that MCM8IP directly associates with MCM8-9, a helicase complex mutated in primary ovarian insufficiency, and RPA1. We additionally show that the interactions of MCM8IP with MCM8-9 and RPA facilitate HR and promote replication fork progression and cellular viability in response to treatment with crosslinking agents. Mechanistically, MCM8IP stimulates the helicase activity of MCM8-9. Collectively, our work identifies MCM8IP as a key regulator of DNA damage-associated DNA synthesis during DNA recombination and replication.

INSTRUMENT(S): Orbitrap Fusion, Q Exactive HF

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture

SUBMITTER: Alberto Ciccia  

LAB HEAD: Alberto Ciccia

PROVIDER: PXD019156 | Pride | 2020-06-15

REPOSITORIES: Pride