title: ATR-dependent checkpoint modulates XPA nuclear import in response to UV irradiation.
abstract: In response to DNA damage, mammalian cells activate various DNA repair pathways to remove DNA lesions and, meanwhile, halt cell cycle progressions to allow sufficient time for repair. The nucleotide excision repair (NER) and the ATR-dependent cell cycle checkpoint activation are two major cellular responses to DNA damage induced by UV irradiation. However, how these two processes are coordinated in the response is poorly understood. Here we showed that the essential NER factor XPA (xeroderma pigmentosum group A) underwent nuclear accumulation upon UV irradiation, and strikingly, such an event occurred in an ATR (Ataxia-Telangiectasia mutated and RAD3-related)-dependent manner. Either treatment of cells with ATR kinase inhibitors or transfection of cells with small interfering RNA targeting ATR compromised the UV-induced XPA nuclear translocation. Consistently, the ATR-deficient cells displayed no substantial XPA nuclear translocation while the translocation remained intact in ATM (Ataxia-Telangiectasia mutated)-deficient cells in response to UV irradiation. Moreover, we found that ATR is required for the UV-induced nuclear focus formation of XPA. Taken together, our results suggested that the ATR checkpoint pathway may modulate NER activity through the regulation of XPA redistribution in human cells upon UV irradiation.
authors.affiliation: Department of Biochemistry and Molecular Biology, James H Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.
authors.forename: X
authors.initials: X
authors.lastname: Wu
authors.forename: S M
authors.initials: SM
authors.lastname: Shell
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Zou
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000528:radiation effects*; D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D001260:Ataxia Telangiectasia; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism / Q000528:radiation effects*; D004249:DNA Damage; D004260:DNA Repair; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D005455:Fluorescent Antibody Technique; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000494:pharmacology; D014162:Transfection; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D014466:Ultraviolet Rays; D051760:Xeroderma Pigmentosum Group A Protein / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D034741:RNA, Small Interfering; D025521:Tumor Suppressor Proteins; C497314:XPA protein, human; D051760:Xeroderma Pigmentosum Group A Protein; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases