title: DDB2 complex-mediated ubiquitylation around DNA damage is oppositely regulated by XPC and Ku and contributes to the recruitment of XPA.
abstract: UV-damaged-DNA-binding protein (UV-DDB) is a heterodimer comprised of DDB1 and DDB2 and integrated in a complex that includes a ubiquitin ligase component, cullin 4A, and Roc1. Here we show that the ubiquitin ligase activity of the DDB2 complex is required for efficient global genome nucleotide excision repair (GG-NER) in chromatin. Mutant DDB2 proteins derived from xeroderma pigmentosum group E patients are not able to mediate ubiquitylation around damaged sites in chromatin. We also found that CSN, a negative regulator of cullin-based ubiquitin ligases, dissociates from the DDB2 complex when the complex binds to damaged DNA and that XPC and Ku oppositely regulate the ubiquitin ligase activity, especially around damaged sites. Furthermore, the DDB2 complex-mediated ubiquitylation plays a role in recruiting XPA to damaged sites. These findings shed some light on the early stages of GG-NER.
authors.affiliation: Graduate School of Frontier Biosciences, Osaka University, Yamadaoka 1-3, Suita, Osaka 565-0871, Japan.
authors.forename: Arato
authors.initials: A
authors.lastname: Takedachi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Saijo
authors.forename: Kiyoji
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D034961:Antigens, Nuclear / Q000235:genetics / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006657:Histones / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D000072200:Ku Autoantigen; D008962:Models, Theoretical; D009154:Mutation; D009707:Nucleosomes / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D054875:Ubiquitination; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum / Q000235:genetics / Q000378:metabolism; D051760:Xeroderma Pigmentosum Group A Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D034961:Antigens, Nuclear; D002843:Chromatin; C117669:DDB2 protein, human; D004268:DNA-Binding Proteins; D006657:Histones; D009707:Nucleosomes; D034741:RNA, Small Interfering; D051760:Xeroderma Pigmentosum Group A Protein; C086984:XPC protein, human; D044767:Ubiquitin-Protein Ligases; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen