title: Introduced T cell receptor variable region gene segments recombine in pre-B cells: evidence that B and T cells use a common recombinase.
abstract: We have recently proposed that a common recombinase performs all of the many variable region gene assembly events in B and T cells, and that the specificity of these joining events is mediated by regulating the "accessibility" of the involved gene segments. To test this possibility, we have introduced "accessible" T cell receptor (TCR) variable region gene segments into a pre-B cell line capable of recombining endogenous and transfected immunoglobulin (Ig) variable region gene segments. Although the corresponding "inaccessible" endogenous TCR gene segments do not rearrange in this line or in B cells in general, the introduced TCR gene segments join very frequently and, in fact, closely resemble introduced Ig gene segments in their recombination characteristics. These observations suggest a new role for conventional Ig transcriptional enhancers--recombinational enhancement. Our studies provide insight into additional aspects of the joining mechanism such as N region insertion, aberrant joining, and recombination-recognition sequence requirements for joining.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D001483:Base Sequence; D002478:Cells, Cultured; D004254:DNA Nucleotidyltransferases / Q000235:genetics*; D003851:Deoxyribonucleases; D005786:Gene Expression Regulation; D005818:Genetic Engineering; D007136:Immunoglobulins / Q000235:genetics*; D051379:Mice; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D011995:Recombination, Genetic; D013601:T-Lymphocytes / Q000502:physiology*; D045567:VDJ Recombinases
chemical_list: D007136:Immunoglobulins; D011948:Receptors, Antigen, T-Cell; D004254:DNA Nucleotidyltransferases; D045567:VDJ Recombinases; D003851:Deoxyribonucleases