RAG1/2 induces genomic insertions by mobilizing DNA into RAG1/2-independent breaks.
The RAG recombinase (RAG1/2) plays an essential role in adaptive immunity by mediating V(D)J recombination in developing lymphocytes. In contrast, aberrant RAG1/2 activity promotes lymphocyte malignancies by causing chromosomal translocations and DNA deletions at cancer genes. RAG1/2 can also induce genomic DNA insertions by transposition and trans-V(D)J recombination, but only few such putative events have been documented in vivo. We used next-generation sequencing techniques to examine chromosomal rearrangements in primary murine B cells and discovered that RAG1/2 causes aberrant insertions by releasing cleaved antibody gene fragments that subsequently reintegrate into DNA breaks induced on a heterologous chromosome. We confirmed that RAG1/2 also mobilizes genomic DNA into independent physiological breaks by identifying similar insertions in human lymphoma and leukemia. Our findings reveal a novel RAG1/2-mediated insertion pathway distinct from DNA transposition and trans-V(D)J recombination that destabilizes the genome and shares features with reported oncogenic DNA insertions.
Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065.
Philipp C
0000-0002-9790-4086
PC
Rommel
Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065.
Thiago Y
0000-0002-2654-0879
TY
Oliveira
Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065 drobbiani@rockefeller.edu nussen@rockefeller.edu.|Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065.
Michel C
0000-0003-0592-8564
MC
Nussenzweig
Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065 drobbiani@rockefeller.edu nussen@rockefeller.edu.
Davide F
0000-0001-7379-3484
DF
Robbiani
D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000502:physiology*; D042822:Genomic Instability; D018398:Homeodomain Proteins / Q000502:physiology*; D007136:Immunoglobulins / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D016254:Mutagenesis, Insertional; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D014178:Translocation, Genetic; D060152:V(D)J Recombination
D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C014609:IgK; D007136:Immunoglobulins; C499308:Rag2 protein, mouse; D011948:Receptors, Antigen, T-Cell; C064658:RAG-1 protein