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A Novel Role for the MRN‐CtIP complex in Schizosaccharomyces pombe Non‐Homologous End‐Joining (NHEJ)
Author(s) -
Li Yanhui,
Runge Kurt
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.539.3
Subject(s) - rad50 , schizosaccharomyces pombe , biology , homologous recombination , dna repair , non homologous end joining , saccharomyces cerevisiae , schizosaccharomyces , plasmid , transposable element , genetics , dna , microbiology and biotechnology , genome , yeast , gene , dna binding protein , transcription factor
Objective To elucidate the mechanisms for that allow Hermes transposon excision from the S. pombe genome. Results MRN (Mre11‐Rad50‐Nbs1) ‐CtIP complexes are key players in double‐strand break repair from yeasts to humans. The role of MRN‐CtIP in NHEJ is unclear owing to the differing results in Saccharomyces cerevisiae and S. pombe : while both yeasts require Ku and DNA ligase IV to join the ends of transfected linear plasmids, only S. cerevisiae requires its MRN‐CtIP complex. The excision of the hAT transposon Hermes uncovered a role for MRN‐CtIP in S. pombe NHEJ. hAT transposons produce an 8 bp target site duplication (TSD) upon insertion, and excise by forming DNA hairpins on each side of the chromosomal break. In Maize and Drosophila , hAT transposon excision yields NHEJ repair events that retain both TSDs, while S. cerevisiae events have much larger deletions. In S. pombe , excision yields repair events that retain both TSDs, and efficient repair requires Ku70, DNA ligase IV and each component of MRN‐CtIP. Mutants that eliminate Mre11 dimerization, but not those that eliminate Mre11 nuclease activities, also greatly reduce repair. Conclusion S. pombe does utilize its MRN‐CtIP complex for NHEJ, and the Mre11 dimerization domain plays an important role. Repair events in S. pombe are more similar to those in metazoans compared to the events in S. cerevisiae , which show a greater amount of resection prior to end‐joining. Source of research support: NIH R01GM050752 and NIH R01AG019960