title: The RING finger protein RNF8 ubiquitinates Nbs1 to promote DNA double-strand break repair by homologous recombination.
abstract: Ubiquitination plays an important role in the DNA damage response. We identified a novel interaction of the E3 ubiquitin ligase RNF8 with Nbs1, a key regulator of DNA double-strand break (DSB) repair. We found that Nbs1 is ubiquitinated both before and after DNA damage and is a direct ubiquitination substrate of RNF8. We also identified key residues on Nbs1 that are ubiquitinated by RNF8. By using laser microirradiation and live-cell imaging, we observed that RNF8 and its ubiquitination activity are important for promoting optimal binding of Nbs1 to DSB-containing chromatin. We also demonstrated that RNF8-mediated ubiquitination of Nbs1 contributes to the efficient and stable binding of Nbs1 to DSBs and is important for HR-mediated DSB repair. Taken together, these studies suggest that Nbs1 is one important target of RNF8 to regulate DNA DSB repair.
authors.affiliation: Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: Chi-Sheng
authors.initials: CS
authors.lastname: Lu
authors.forename: Lan N
authors.initials: LN
authors.lastname: Truong
authors.forename: Aaron
authors.initials: A
authors.lastname: Aslanian
authors.forename: Linda Z
authors.initials: LZ
authors.lastname: Shi
authors.forename: Yongjiang
authors.initials: Y
authors.lastname: Li
authors.forename: Patty Yi-Hwa
authors.initials: PY
authors.lastname: Hwang
authors.forename: Kwi Hye
authors.initials: KH
authors.lastname: Koh
authors.forename: Tony
authors.initials: T
authors.lastname: Hunter
authors.forename: John R
authors.initials: JR
authors.lastname: Yates
authors.forename: Michael W
authors.initials: MW
authors.lastname: Berns
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Wu
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair / Q000502:physiology* / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D059765:Homologous Recombination / Q000502:physiology* / Q000528:radiation effects; D006801:Humans; D007834:Lasers / Q000009:adverse effects; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases; D054875:Ubiquitination / Q000502:physiology* / Q000528:radiation effects
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C112156:NBN protein, human; D009687:Nuclear Proteins; C486521:RNF8 protein, human; D044767:Ubiquitin-Protein Ligases