1. Chromatin assembly factor 1 subunit A promotes TLS pathway by recruiting E3 ubiquitin ligase RAD18 in cancer cells.
- Author
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Wen B, Zheng HX, Heng JH, Tang Q, Deng DX, Zhang ZD, Liao LD, Xu LY, and Li EM
- Subjects
- Humans, Neoplasms metabolism, Neoplasms genetics, Neoplasms pathology, Cell Line, Tumor, Animals, Protein Binding, Ubiquitin-Protein Ligases metabolism, Ubiquitin-Protein Ligases genetics, Chromatin Assembly Factor-1 metabolism, Chromatin Assembly Factor-1 genetics, Proliferating Cell Nuclear Antigen metabolism, DNA Replication, DNA Damage, Ubiquitination, DNA-Binding Proteins metabolism, DNA-Binding Proteins genetics
- Abstract
The translesion DNA synthesis (TLS) pathway mediated by proliferating cell nuclear antigen (PCNA) monoubiquitination is an essential mechanism by which cancer cells bypass DNA damage caused by DNA damage to maintain genomic stability and cell survival. Chromatin assembly factor 1 subunit A (CHAF1A) traditionally promotes histone assembly during DNA replication. Here, we revealed that CHAF1A is a novel regulator of the TLS pathway in cancer cells. CHAF1A promotes restart and elongation of the replication fork under DNA replication stress. Mechanistically, the C-terminal domain of CHAF1A directly interacts with E3 ubiquitin ligase RAD18, enhancing RAD18 binding on the stalled replication fork. CHAF1A facilitates PCNA K164 monoubiquitination mediated by RAD18, thereby promoting the recruitment of Y-family DNA polymerases and enhancing cancer cell resistance to DNA damage. In addition, CHAF1A-mediated RAD18 recruitment and PCNA monoubiquitination are independent of the CHAF1A-PCNA interaction and its histone assembly function. Taken together, these findings improve our understanding of the mechanisms that regulate the TLS pathway and provide insights into the relationship between CHAF1A and DNA replication stress in cancer cells., Competing Interests: Competing interests: The authors declare no competing interests. Ethics approval and consent to participate: All methods were performed in accordance with the relevant guidelines and regulations. This study did not involve any animal and human cancer patients., (© 2025. The Author(s).)
- Published
- 2025
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