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Early Role of Rif1 in the Repair of P‐element Transposase‐Induced DNA Double Strand Breaks
Author(s) -
Krishnamurthy Manan,
Blanch Justin,
Maclay Tyler,
McVey Mitch
Publication year - 2021
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.2021.35.s1.01601
Subject(s) - transposase , biology , dna repair , microbiology and biotechnology , homology directed repair , homologous recombination , dna , ku80 , mutant , nucleotide excision repair , dna damage , saccharomyces cerevisiae , genetics , transposable element , dna binding protein , transcription factor , yeast , gene
Rap1 interacting factor (RIF1) is a structurally well‐conserved protein in eukaryotes that plays an important role in pathway choice during the repair of DNA double strand breaks (DSBs). In human cells, Rif1 directly interacts with phosphorylated p53 binding protein (53BP1) to inhibit BRCA1 mediated resection of DSBs during G1, and hence promotes repair via non‐homologous end joining. In contrast, Saccharomyces cerevisiae Rif1 was shown to promote resection and homology‐directed repair of DSBs in both G1 and G2. Given the opposing repair functions of Rif1 in evolutionary distant mammalian and yeast cells, we have explored the DSB repair role of Rif1 in phylogenetic intermediate Drosophila melanogaster. Hatching assays and irradiation sensitivity assays were conducted to determine whether rif1 mutant fly stocks exhibit any DSB repair defect during embryonic development or larval development. No such defect was observed. Next, in order to probe whether Rif1 influences repair pathway choice, as is seen in mammals and yeast, DSB repair assays were conducted. These assays allow for the determination of repair mechanism—end‐joining or homology‐directed repair—of site‐specific DSBs in the male germ‐line. rif1 mutants exhibited no defects in the repair of I‐ Sce I endonuclease‐induced breaks but, interestingly, a near‐complete defect in the repair of P ‐element transposase‐induced breaks. These results suggest that Drosophila RIF1 plays an early role in the repair of P‐ element transposase‐induced breaks and may provide insight into the disparate roles of RIF1 in yeast and mammals.