Cyclin-dependent kinase-mediated phosphorylation of FANCD2 promotes mitotic fidelity
Date of Original Version
Fanconi anemia (FA) is a rare genetic disease characterized by increased risk for bone marrow failure and cancer. The FA proteins function together to repair damaged DNA. A central step in the activation of the FA pathway is the monoubiquitination of the FANCD2 and FANCI proteins, which occurs upon exposure to DNA-damaging agents and during the S phase of the cell cycle. The regulatory mechanisms governing S-phase monoubiquitination, in particular, are poorly understood. In this study, we have identified a cyclin-dependent kinase (CDK) regulatory phosphosite (S592) proximal to the site of FANCD2 monoubiquitination. FANCD2 S592 phosphorylation was detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and by immunoblotting with an S592 phospho-specific antibody. Mutation of S592 leads to abrogated monoubiquitination of FANCD2 during the S phase. Furthermore, FA-D2 (FANCD22/2) patient cells expressing S592 mutants display reduced proliferation under conditions of replication stress and increased mitotic aberrations, including micronuclei and multinucleated cells. Our findings describe a novel cell cycle-specific regulatory mechanism for the FANCD2 protein that promotes mitotic fidelity.
Publication Title, e.g., Journal
Molecular and Cellular Biology
Cantres-Velez, Juan A., Justin L. Blaize, David A. Vierra, Rebecca A. Boisvert, Jada L. Garzon, Benjamin Piraino, Winnie Tan, Andrew J. Deans, and Niall G. Howlett. "Cyclin-dependent kinase-mediated phosphorylation of FANCD2 promotes mitotic fidelity." Molecular and Cellular Biology 41, 8 (2021). doi: 10.1128/MCB.00234-21.