In vivo transposition mediated by V(D)J recombinase in human T lymphocytes.
The rearrangement of immunoglobulin (Ig) and T-cell receptor (TCR) genes in lymphocytes by V(D)J recombinase is essential for immunological diversity in humans. These DNA rearrangements involve cleavage by the RAG1 and RAG2 (RAG1/2) recombinase enzymes at recombination signal sequences (RSS). This reaction generates two products, cleaved signal ends and coding ends. Coding ends are ligated by non-homologous end-joining proteins to form a functional Ig or TCR gene product, while the signal ends form a signal joint. In vitro studies have demonstrated that RAG1/2 are capable of mediating the transposition of cleaved signal ends into non-specific sites of a target DNA molecule. However, to date, in vivo transposition of signal ends has not been demonstrated. We present evidence of in vivo inter-chromosomal transposition in humans mediated by V(D)J recombinase. T-cell isolates were shown to contain TCRalpha signal ends from chromosome 14 inserted into the X-linked hypo xanthine-guanine phosphoribosyl transferase locus, resulting in gene inactivation. These findings implicate V(D)J recombinase-mediated transposition as a mutagenic mechanism capable of deleterious genetic rearrangements in humans.
Messier
Terri L
TL
Department of Pediatrics, University of Vermont, Burlington, VT 05405, USA.
O'Neill
J Patrick
JP
Hou
Sai-Mei
SM
Nicklas
Janice A
JA
Finette
Barry A
BA
D001483:Base Sequence; D001665:Binding Sites; D002883:Chromosomes, Human, Pair 14; D041321:Chromosomes, Human, X; D002999:Clone Cells; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D015329:Gene Rearrangement, T-Lymphocyte; D020868:Gene Silencing; D005803:Genes, Immunoglobulin; D019673:Genes, T-Cell Receptor alpha; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D007133:Immunoglobulin Joining Region / Q000235:genetics / Q000276:immunology; D008957:Models, Genetic; D008969:Molecular Sequence Data; D011948:Receptors, Antigen, T-Cell; D011995:Recombination, Genetic; D013601:T-Lymphocytes / Q000201:enzymology* / Q000276:immunology; D045567:VDJ Recombinases
D018398:Homeodomain Proteins; D007133:Immunoglobulin Joining Region; D011948:Receptors, Antigen, T-Cell; D007041:Hypoxanthine Phosphoribosyltransferase; D004254:DNA Nucleotidyltransferases; D045567:VDJ Recombinases