title: SIRT1 regulates UV-induced DNA repair through deacetylating XPA.
abstract: SIRT1, a NAD(+)-dependent histone deacetylase, plays crucial roles in multiple biological processes including gene transcription, cellular metabolism, stress response, and tumorigenesis. Xeroderma pigmentosum group A (XPA) is a core nucleotide excision repair (NER) factor essential for NER process. Here we show that SIRT1 plays an important role in the regulation of NER pathway. Downregulation of SIRT1 significantly sensitizes cells to UV irradiation. SIRT1 interacts with XPA, and the interaction is enhanced after UV irradiation. XPA can be acetylated at lysines 63 and 67. SIRT1 deacetylates XPA both in vitro and in cells. Importantly, SIRT1-mediated deacetylation of XPA is required for optimal NER pathway since XPA-deficient cells complemented with XPA-K6367Q, which mimics hyperacetylated XPA, display significantly higher UV sensitivity compared with the XPA cells complemented with wild-type XPA. Furthermore, SIRT1-mediated XPA deacetylation enhances its interaction with RPA32. Our results demonstrate that SIRT1 regulates NER pathway through modulation of XPA acetylation status.
authors.affiliation: Department of Cancer Biology and the Cancer Center, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Fan
authors.forename: Jianyuan
authors.initials: J
authors.lastname: Luo
mesh_terms: D000107:Acetylation; D004260:DNA Repair / Q000235:genetics / Q000528:radiation effects*; D005816:Genetic Complementation Test; D006367:HeLa Cells; D006801:Humans; D020125:Mutation, Missense; D011499:Protein Processing, Post-Translational / Q000235:genetics / Q000528:radiation effects*; D051716:Replication Protein A / Q000235:genetics / Q000378:metabolism; D056564:Sirtuin 1 / Q000235:genetics / Q000378:metabolism*; D014466:Ultraviolet Rays; D051760:Xeroderma Pigmentosum Group A Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D051716:Replication Protein A; C497314:XPA protein, human; D051760:Xeroderma Pigmentosum Group A Protein; C516794:RPA2 protein, human; C447939:SIRT1 protein, human; D056564:Sirtuin 1