Induction of homologous recombination between sequence repeats by the activation induced cytidine deaminase (AID) protein

Elife. 2014 Jul 8:3:e03110. doi: 10.7554/eLife.03110.

Abstract

The activation induced cytidine deaminase (AID) protein is known to initiate somatic hypermutation, gene conversion or switch recombination by cytidine deamination within the immunoglobulin loci. Using chromosomally integrated fluorescence reporter transgenes, we demonstrate a new recombinogenic activity of AID leading to intra- and intergenic deletions via homologous recombination of sequence repeats. Repeat recombination occurs at high frequencies even when the homologous sequences are hundreds of bases away from the positions of AID-mediated cytidine deamination, suggesting DNA end resection before strand invasion. Analysis of recombinants between homeologous repeats yielded evidence for heteroduplex formation and preferential migration of the Holliday junctions to the boundaries of sequence homology. These findings broaden the target and off-target mutagenic potential of AID and establish a novel system to study induced homologous recombination in vertebrate cells.DOI: http://dx.doi.org/10.7554/eLife.03110.001.

Keywords: AID; DNA repair; homologous recombination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B-Lymphocytes / immunology
  • B-Lymphocytes / metabolism
  • Base Sequence
  • Cell Line
  • Chickens
  • Crossing Over, Genetic
  • Cytidine Deaminase / metabolism*
  • Gene Conversion
  • Genes, Reporter
  • Green Fluorescent Proteins / genetics
  • Homologous Recombination*
  • Humans
  • Immunoglobulin Switch Region
  • Luminescent Proteins / genetics
  • Mice
  • Models, Genetic
  • Molecular Sequence Data
  • Nucleic Acid Heteroduplexes / genetics
  • Recombinational DNA Repair
  • Red Fluorescent Protein
  • Repetitive Sequences, Nucleic Acid
  • Sequence Deletion
  • Sequence Homology, Nucleic Acid
  • Somatic Hypermutation, Immunoglobulin

Substances

  • Luminescent Proteins
  • Nucleic Acid Heteroduplexes
  • Green Fluorescent Proteins
  • AICDA (activation-induced cytidine deaminase)
  • Cytidine Deaminase