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Chen L, Bellone RR, Wang Y, Singer-Berk M, Sugasawa K, Ford JM, Artandi SE. A novel DDB2 mutation causes defective recognition of UV-induced DNA damages and prevalent equine squamous cell carcinoma. DNA Repair (Amst) 2020; 97:103022. [PMID: 33276309 DOI: 10.1016/j.dnarep.2020.103022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/22/2020] [Accepted: 11/09/2020] [Indexed: 02/06/2023]
Abstract
Squamous cell carcinoma (SCC) occurs frequently in the human Xeroderma Pigmentosum (XP) syndrome and is characterized by deficient UV-damage repair. SCC is the most common equine ocular cancer and the only associated genetic risk factor is a UV-damage repair protein. Specifically, a missense mutation in horse DDB2 (T338M) was strongly associated with both limbal SCC and third eyelid SCC in three breeds of horses (Halflinger, Belgian, and Rocky Mountain Horses) and was hypothesized to impair binding to UV-damaged DNA. Here, we investigate DDB2-T338M mutant's capacity to recognize UV lesions in vitro and in vivo, together with human XP mutants DDB2-R273H and -K244E. We show that the recombinant DDB2-T338M assembles with DDB1, but fails to show any detectable binding to DNA substrates with or without UV lesions, due to a potential structural disruption of the rigid DNA recognition β-loop. Consistently, we demonstrate that the cellular DDB2-T338M is defective in its recruitment to focally radiated DNA damages, and in its access to chromatin. Thus, we provide direct functional evidence indicating the DDB2-T338M recapitulates molecular defects of human XP mutants, and is the causal loss-of-function allele that gives rise to equine ocular SCCs. Our findings shed new light on the mechanism of DNA recognition by UV-DDB and on the initiation of ocular malignancy.
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Affiliation(s)
- Lu Chen
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Rebecca R Bellone
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA; Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA
| | - Yan Wang
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Moriel Singer-Berk
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA; Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA
| | - Kaoru Sugasawa
- Biosignal Research Center, Kobe University, Kobe, Hyogo 657-8501, Japan
| | - James M Ford
- Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA 94304, USA
| | - Steven E Artandi
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
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Adam S, Polo SE. Chromatin dynamics during nucleotide excision repair: histones on the move. Int J Mol Sci 2012; 13:11895-11911. [PMID: 23109890 PMCID: PMC3472782 DOI: 10.3390/ijms130911895] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 09/06/2012] [Accepted: 09/07/2012] [Indexed: 12/16/2022] Open
Abstract
It has been a long-standing question how DNA damage repair proceeds in a nuclear environment where DNA is packaged into chromatin. Several decades of analysis combining in vitro and in vivo studies in various model organisms ranging from yeast to human have markedly increased our understanding of the mechanisms underlying chromatin disorganization upon damage detection and re-assembly after repair. Here, we review the methods that have been developed over the years to delineate chromatin alterations in response to DNA damage by focusing on the well-characterized Nucleotide Excision Repair (NER) pathway. We also highlight how these methods have provided key mechanistic insight into histone dynamics coupled to repair in mammals, raising new issues about the maintenance of chromatin integrity. In particular, we discuss how NER factors and central players in chromatin dynamics such as histone modifiers, nucleosome remodeling factors, and histone chaperones function to mobilize histones during repair.
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Affiliation(s)
- Salomé Adam
- Laboratory of Chromatin Dynamics, Curie Institute Research Centre, 75248 Paris Cedex 5, France; E-Mail:
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 218, 75248 Paris Cedex 5, France
| | - Sophie E. Polo
- Laboratory of Chromatin Dynamics, Curie Institute Research Centre, 75248 Paris Cedex 5, France; E-Mail:
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 218, 75248 Paris Cedex 5, France
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +33-1-5624-6721; Fax: +33-1-4633-3016
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