DNA damage-induced phosphorylation of a replicative DNA helicase results in inhibition of DNA replication through attenuation of helicase function.

Autor:	Homiski C; Departments of Microbiology & Immunology and Biochemistry, and the Witebsky Center for Microbial Pathogenesis & Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York at Buffalo, Buffalo, NY 14203, USA., Dey-Rao R; Departments of Microbiology & Immunology and Biochemistry, and the Witebsky Center for Microbial Pathogenesis & Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York at Buffalo, Buffalo, NY 14203, USA., Shen S; Department of Pharmaceutical Sciences, University at Buffalo, State University of New York at Buffalo, Buffalo, NY 14203, USA; NYS Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY 14203, USA., Qu J; Department of Pharmaceutical Sciences, University at Buffalo, State University of New York at Buffalo, Buffalo, NY 14203, USA; NYS Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY 14203, USA., Melendy T; Departments of Microbiology & Immunology and Biochemistry, and the Witebsky Center for Microbial Pathogenesis & Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York at Buffalo, Buffalo, NY 14203, USA.
Jazyk:	angličtina
Zdroj:	Nucleic acids research [Nucleic Acids Res] 2024 Sep 23; Vol. 52 (17), pp. 10311-10328.
DOI:	10.1093/nar/gkae663
Abstrakt:	A major function of the DNA damage responses (DDRs) that act during the replicative phase of the cell cycle is to inhibit initiation and elongation of DNA replication. It has been shown that DNA replication of the polyomavirus, SV40, is inhibited and its replication fork is slowed by cellular DDR responses. The inhibition of SV40 DNA replication is associated with enhanced DDR kinase phosphorylation of SV40 Large T-antigen (LT), the viral DNA helicase. Mass spectroscopy was used to identify a novel highly conserved DDR kinase site, T518, on LT. In cell-based assays expression of a phosphomimetic form of LT at T518 (T518D) resulted in dramatically decreased levels of SV40 DNA replication, but LT-dependent transcriptional activation was unaffected. Purified WT and LT T518D were analyzed in vitro. In concordance with the cell-based data, reactions using SV40 LT-T518D, but not T518A, showed dramatic inhibition of SV40 DNA replication. A myriad of LT protein-protein interactions and LT's biochemical functions were unaffected by the LT T518D mutation; however, LT's DNA helicase activity was dramatically decreased on long, but not very short, DNA templates. These results suggest that DDR phosphorylation at T518 inhibits SV40 DNA replication by suppressing LT helicase activity. (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu