Microhomology-mediated End Joining and Homologous Recombination share the initial end resection step to repair DNA double-strand breaks in mammalian cells.

ABSTRACT: Microhomology-mediated end joining (MMEJ) is a major pathway for Ku-independent alternative nonhomologous end joining, which contributes to chromosomal translocations and telomere fusions, but the underlying mechanism of MMEJ in mammalian cells is not well understood. In this study, we demonstrated that, distinct from Ku-dependent classical nonhomologous end joining, MMEJ--even with very limited end resection--requires cyclin-dependent kinase activities and increases significantly when cells enter S phase. We also showed that MMEJ shares the initial end resection step with homologous recombination (HR) by requiring meiotic recombination 11 homolog A (Mre11) nuclease activity, which is needed for subsequent recruitment of Bloom syndrome protein (BLM) and exonuclease 1 (Exo1) to DNA double-s

SUBMITTER: Truong LN 

PROVIDER: S-EPMC3651503 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature