Non-homologous end joining often uses microhomology: implications for alternative end joining

DNA Repair (Amst). 2014 May;17:74-80. doi: 10.1016/j.dnarep.2014.02.006. Epub 2014 Mar 7.

Abstract

Artemis and PALF (also called APLF) appear to be among the primary nucleases involved in non-homologous end joining (NHEJ) and responsible for most nucleolytic end processing in NHEJ. About 60% of NHEJ events show an alignment of the DNA ends that use 1 or 2bp of microhomology (MH) between the two DNA termini. Thus, MH is a common feature of NHEJ. For most naturally occurring human chromosomal deletions (e.g., after oxidative damage or radiation) and translocations, such as those seen in human neoplasms and as well as inherited chromosomal structural variations, MH usage occurs at a frequency that is typical of NHEJ, and does not suggest major involvement of alternative pathways that require more extensive MH. Though we mainly focus on human NHEJ at double-strand breaks, comparison on these points to other eukaryotes, primarily S. cerevisiae, is informative.

Keywords: Double-strand break repair, Lymphoma, Chromosomal rearrangements, V(D)J recombination, Class switch recombination.

Publication types

  • Review

MeSH terms

  • Animals
  • Chromosomal Instability
  • Chromosomes
  • DNA Breaks, Double-Stranded*
  • DNA End-Joining Repair*
  • DNA Repair Enzymes / metabolism
  • Humans
  • Recombination, Genetic
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / metabolism
  • Sequence Homology, Nucleic Acid*
  • Vertebrates / genetics
  • Vertebrates / metabolism

Substances

  • Saccharomyces cerevisiae Proteins
  • DNA Repair Enzymes