title: N segment insertion and region-directed somatic hypermutation in a kappa gene of a t(2;8) chromosomal translocation.
abstract: A detailed molecular analysis of both reciprocal recombination products of the variant t(2;8) chromosomal translocation of the Burkitt lymphoma derived cell line JI and their germline counterparts was carried out. The breakpoint on chromosome 8 is localized 28 kb to the 3' side of the c-myc protooncogene, the breakpoint on chromosome 2 was found to be within an aberrantly rearranged VK gene (abbreviations ref. 1). Novel features of the immunoglobulin moiety involved in this process include insertion of extra nucleotides in the V-J junction which have the characteristics of a N segment as it has been found up to now only in heavy chain and T cell receptor genes; the occurrence of somatic mutations in 8q+ and not in 2p-. These data allow a reconstruction of the course of events in the cell line JI; remarkable sequence regularities at the chromosomal breakpoints consisting of symmetrically placed dinucleotides and elements related to the hepta- and nonanucleotide recombinase recognition sequences are discussed in the context of the translocation mechanism.
mesh_terms: D001483:Base Sequence; D002051:Burkitt Lymphoma / Q000235:genetics; D002460:Cell Line; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2 / Q000648:ultrastructure*; D002898:Chromosomes, Human, Pair 8 / Q000648:ultrastructure*; D004254:DNA Nucleotidyltransferases / Q000502:physiology; D005796:Genes; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc; D011995:Recombination, Genetic; D014178:Translocation, Genetic; D045567:VDJ Recombinases
chemical_list: D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D004254:DNA Nucleotidyltransferases; D045567:VDJ Recombinases