Antigen receptor genes and the evolution of a recombinase.
Antigen receptor genes exist in the germline in a "split" configuration and are assembled in developing B and T lymphocytes by V(D)J recombination. This site-specific recombination reaction is initiated by a complex containing the RAG1 and RAG2 proteins and completed by general DNA repair factors. RAG1 and RAG2, like the adaptive immune system itself, are found exclusively in jawed vertebrates, and are thought to have entered the vertebrate genome by horizontal transmission as components of a transposable element. This review discusses the structure of antigen receptor genes and the mechanisms by which they are assembled and diversified, and then goes on to consider the evolutionary implications of the arrival of the hypothetical "RAG transposon".
Schatz
David G
DG
Section of Immunobiology, Howard Hughes Medical Institute, Yale University School of Medicine, 300 Cedar Street, New Haven, CT 06510, USA. david.schatz@vale.edu
D000818:Animals; D004260:DNA Repair / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D019143:Evolution, Molecular; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D019672:Genes, T-Cell Receptor; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D045522:Recombinases / Q000235:genetics / Q000502:physiology; D019895:Transposases / Q000235:genetics / Q000502:physiology; D014714:Vertebrates / Q000235:genetics / Q000276:immunology*
D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D045522:Recombinases; C064655:V(D)J recombination activating protein 2; C064658:RAG-1 protein; D019895:Transposases