RAD18 O-GlcNAcylation promotes translesion DNA synthesis and homologous recombination repair

• Published in: Cell death & disease Vol. 15; no. 5; pp. 321 - 11
• Main Authors: Ma, Xiaolu, Fu, Hui, Sun, Chenyi, Wu, Wei, Hou, Wenya, Zhou, Zibin, Zheng, Hui, Gong, Yifei, Wu, Honglin, Qin, Junying, Lou, Huiqiang, Li, Jing, Tang, Tie-Shan, Guo, Caixia
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08.05.2024; Springer Nature B.V; Nature Publishing Group
• Subjects: 13/1; 13/89; 631/337/1427/2354; 631/337/458/1524; 82/80; 82/83; 96/109; 96/63; Acetylglucosamine - metabolism; Antibodies; Biochemistry; Biomedical and Life Sciences; Biotechnology; Cell Biology; Cell Culture; Cell cycle; Cell Cycle Proteins - genetics; Cell Cycle Proteins - metabolism; Cloning; DNA - metabolism; DNA biosynthesis; DNA Breaks, Double-Stranded; DNA Damage; DNA repair; DNA Replication; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; DNA-Directed DNA Polymerase - metabolism; Genomes; Glycosylation; HEK293 Cells; Homologous recombination; Homologous recombination repair; Humans; Immunology; Kinases; Laboratories; Lasers; Life Sciences; N-Acetylglucosamine; O-GlcNAcylation; Phosphorylation; Plasmids; Proliferating Cell Nuclear Antigen - metabolism; Protein Binding; Proteins; Rad51 Recombinase - metabolism; Recombinational DNA Repair; Regulation; Translesion DNA Synthesis; Ubiquitin-protein ligase; Ubiquitin-Protein Ligases - metabolism; Ubiquitination; Ultraviolet Rays
• ISSN: 2041-4889; 2041-4889
• DOI: 10.1038/s41419-024-06700-y

RAD18, an important ubiquitin E3 ligase, plays a dual role in translesion DNA synthesis (TLS) and homologous recombination (HR) repair. However, whether and how the regulatory mechanism of O-linked N-acetylglucosamine (O-GlcNAc) modification governing RAD18 and its function during these processes remains unknown. Here, we report that human RAD18, can undergo O-GlcNAcylation at Ser130/Ser164/Thr468, which is important for optimal RAD18 accumulation at DNA damage sites. Mechanistically, abrogation of RAD18 O-GlcNAcylation limits CDC7-dependent RAD18 Ser434 phosphorylation, which in turn significantly reduces damage-induced PCNA monoubiquitination, impairs Polη focus formation and enhances UV sensitivity. Moreover, the ubiquitin and RAD51C binding ability of RAD18 at DNA double-strand breaks (DSBs) is O-GlcNAcylation-dependent. O-GlcNAcylated RAD18 promotes the binding of RAD51 to damaged DNA during HR and decreases CPT hypersensitivity. Our findings demonstrate a novel role of RAD18 O-GlcNAcylation in TLS and HR regulation, establishing a new rationale to improve chemotherapeutic treatment.