title: The RecQ helicase RECQL5 participates in psoralen-induced interstrand cross-link repair.
abstract: Interstrand cross-links (ICLs) are very severe lesions as they are absolute blocks of replication and transcription. This property of interstrand cross-linking agents has been exploited clinically for the treatment of cancers and other diseases. ICLs are repaired in human cells by specialized DNA repair pathways including components of the nucleotide excision repair pathway, double-strand break repair pathway and the Fanconi anemia pathway. In this report, we identify the role of RECQL5, a member of the RecQ family of helicases, in the repair of ICLs. Using laser-directed confocal microscopy, we demonstrate that RECQL5 is recruited to ICLs formed by trioxalen (a psoralen-derived compound) and ultraviolet irradiation A. Using single-cell gel electrophoresis and proliferation assays, we identify the role of RECQL5 in the repair of ICL lesions. The domain of RECQL5 that recruits to the site of ICL was mapped to the KIX region between amino acids 500 and 650. Inhibition of transcription and of topoisomerases did not affect recruitment, which was inhibited by DNA-intercalating agents, suggesting that the DNA structure itself may be responsible for the recruitment of RECQL5 to the sites of ICLs.
authors.affiliation: Laboratory of Molecular Gerontology, Biomedical Research Center, National Institute on Aging, 251 Bayview Boulevard, Suite 100, Baltimore, MD 21224, USA.
authors.forename: Mahesh
authors.initials: M
authors.lastname: Ramamoorthy
authors.forename: Alfred
authors.initials: A
authors.lastname: May
authors.forename: Takashi
authors.initials: T
authors.lastname: Tadokoro
authors.forename: Venkateswarlu
authors.initials: V
authors.lastname: Popuri
authors.forename: Michael M
authors.initials: MM
authors.lastname: Seidman
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Croteau
authors.forename: Vilhelm A
authors.initials: VA
authors.lastname: Bohr
mesh_terms: D002460:Cell Line; D003432:Cross-Linking Reagents / Q000633:toxicity*; D004249:DNA Damage / Q000187:drug effects*; D004260:DNA Repair / Q000502:physiology*; D026942:DNA Topoisomerases / Q000378:metabolism; D005090:Exodeoxyribonucleases / Q000378:metabolism; D005363:Ficusin / Q000633:toxicity*; D006801:Humans; D007700:Kinetics; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D053484:RecQ Helicases / Q000737:chemistry / Q000378:metabolism*; D059003:Topoisomerase Inhibitors / Q000494:pharmacology; D014158:Transcription, Genetic; D000071657:Werner Syndrome Helicase
chemical_list: D003432:Cross-Linking Reagents; C506732:RECQL5 protein, human; D059003:Topoisomerase Inhibitors; D005090:Exodeoxyribonucleases; C097151:Bloom syndrome protein; D053484:RecQ Helicases; C098785:WRN protein, human; D000071657:Werner Syndrome Helicase; D026942:DNA Topoisomerases; D005363:Ficusin