The Fanconi anemia (FA) pathway recognizes interstrand DNA crosslinks (ICLs) and contributes to their conversion into double-strand DNA breaks, which can be repaired by homologous recombination. Seven orthologs of the 15 proteins associated with Fanconi anemia are functionally conserved in the model organism C. elegans. Here we report that RNF-113, a ubiquitin ligase, is required for RAD-51 focus formation after inducing ICLs in C. elegans. However, the formation of foci of RPA-1 or FCD-2/FANCD2 in the FA pathway was not affected by depletion of RNF-113. Nevertheless, the RPA-1 foci formed did not disappear with time in the depleted worms, implying serious defects in ICL repair. As a result, RNF-113 depletion increased embryonic lethality after ICL treatment in wild-type worms, but it did not increase the ICL-induced lethality of rfs-1/rad51C mutants. In addition, the persistence of RPA-1 foci was suppressed in doubly-deficient rnf-113;rfs-1 worms, suggesting that there is an epistatic interaction between the two genes. These results lead us to suggest that RNF-113 and RFS-1 interact to promote the displacement of RPA-1 by RAD-51 on single-stranded DNA derived from ICLs.
Bibliographical noteFunding Information:
C. elegans N2, rfs-1(ok1372), and rnf-113(ok1401) strains were provided by the C. elegans Genetics Center (St. Paul, MN), which is funded by NIH Office of Research Infrastructure Programs (P40 OD010440). The fcd-2(tm1298) mutants that had been generated by the National Bioresource Project (Japan), was obtained from Dr. Shohei Mitani (Tokyo Women's Medical University School of Medicine). The monoclonal antibody against α-tubulin developed by Frankel and Nielsen was obtained from the Developmental Studies Hybridoma Bank developed under the auspices of the NICHD and maintained by the University of Iowa, Department of Biological Sciences, Iowa City, IA 52242. We thank Seung-Hoon Lee and Dr. Jong-Bok Yoon (Yonsei Univ.) for helping with ubiquitination assay. Chunkyu Ko, Jinsun Ryu, Ha-Kyeong Jeong, and Dr. Wang-Shick Ryu (Yonsei Univ.) gave technical assistances to experiments.
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)
- Agricultural and Biological Sciences(all)