期刊
GENETICS
卷 176, 期 3, 页码 1403-1415出版社
GENETICS SOCIETY AMERICA
DOI: 10.1534/genetics.107.071621
关键词
-
Two DNA repair pathways are known to mediate DNA double-strand-break (DSB) repair: homologous recombination (HR) and nonhomologous end joining (NHEJ). In addition, a nonconservative backup pathway showing extensive nucleotide loss and relying on microhomologies at repair junctions was identified in NHEJ-deficient cells from a variety of organisms and found to be involved in chromosomal translocations. Here, an extrachromosomal assay was used to characterize this microhomology-mediated end-joining (MMEJ) mechanism in fission yeast. MMEJ was found to require at least five homologous nucleotides and its efficiency was decreased by the presence of nonhomologous nucleotides either within the overlapping sequences or at DSB ends. Exo1 exonuclease and Rad22, a Rad52 homolog, were required for repair, suggesting that MMEJ is related to the single-strand-annealing (SSA) pathway of HR. In addition, MMEJ-dependent repair of DSBs with discontinuous microhomologies was strictly dependent on Po14, a Po1X DNA polymerase. Although not strictly required, Msh2 and Pms1 mismatch repair proteins affected the pattern of MMEJ repair. Strikingly, Pku70 inhibited MMEJ and increased the minimal homology length required for efficient MMEJ. Overall, this study strongly suggests that MMEJ does not define a distinct DSB repair mechanism but reflects micro-SSA.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据