RRC ID 3419
Author Collis SJ, Barber LJ, Ward JD, Martin JS, Boulton SJ.
Title C. elegans FANCD2 responds to replication stress and functions in interstrand cross-link repair.
Journal DNA Repair (Amst.)
Abstract One of the least well understood DNA repair processes in cells is the repair of DNA interstrand cross-links (ICLs) which present a major obstacle to DNA replication and must be repaired or bypassed to allow fork progression. Fanconi anemia (FA) is an inherited genome instability syndrome characterized by hypersensitivity to ICL damage. Central to the FA repair pathway is FANCD2 that is mono-ubiquitylated in response to replication stress and ICL damage through the action of the FA core complex and its E3-ubiquitin ligase subunit, FANCL. In its mono-ubiquitylated form FANCD2 is recruited to repair foci where it is believed to somehow coordinate ICL repair and restart of impeded replication forks. However, the precise mechanism through which the FA pathway and mono-ubiquitylation of FANCD2 promotes ICL repair remains unclear. Here we report on a functional homologue of FANCD2 in C. elegans (FCD-2). Although fcd-2 mutants are homozygous viable, they are exquisitely sensitive to ICL-inducing agents, but insensitive to ionizing radiation (IR). fcd-2 is dispensable for meiotic recombination and activation of the S-phase checkpoint, indicating that ICL sensitivity is likely due to a repair rather than a signalling defect. Indeed, we show that FCD-2 is mono-ubiquitylated in response to ICL damage and is recruited to nuclear repair foci. Consistent with the sensitivity of fcd-2 mutants, FCD-2 focus formation is induced in response to ICL damage and replication stress, but not following IR, suggesting that FCD-2 responds to lesions that block DNA replication and not DNA double strand breaks per se. The realization that the FA pathway is conserved in a genetically tractable model system will permit the comprehensive analysis of the interplay between the FA, homologous recombination (HR), translesion synthesis (TLS) and nucleotide excision repair (NER) pathways, critical to the understanding of ICL repair.
Volume 5(11)
Pages 1398-406
Published 2006-11-8
DOI 10.1016/j.dnarep.2006.06.010
PII S1568-7864(06)00210-2
PMID 16914393
MeSH Amino Acid Sequence Animals Caenorhabditis elegans / drug effects Caenorhabditis elegans / genetics* Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / physiology* Cross-Linking Reagents / pharmacology DNA Repair / drug effects DNA Repair / genetics DNA Repair / physiology* DNA Replication / physiology* Fanconi Anemia Complementation Group D2 Protein / genetics Fanconi Anemia Complementation Group D2 Protein / metabolism Fanconi Anemia Complementation Group D2 Protein / physiology* Models, Genetic Molecular Sequence Data Mutation Prophase / physiology S Phase / physiology Sequence Alignment Ubiquitin / metabolism
IF 4.461
Times Cited 38
C.elegans tm1298 tm853