BCL2 oncogene translocation is mediated by a χ-like consensus

• Published in: The Journal of experimental medicine Vol. 175; no. 6; pp. 1575 - 1588
• Main Authors: WYATT, R. T, RUDDERS, R. A, ZELENETZ, A, DELELLIS, R. A, KRONTIRIS, T. G
• Format: Journal Article
• Language: English
• Published: New York, NY Rockefeller University Press 01.06.1992; The Rockefeller University Press
• Subjects: Base Sequence; Biological and medical sciences; Chromosomes, Human, Pair 22; Chromosomes, Human, Pair 9; DNA, Neoplasm - genetics; DNA, Neoplasm - isolation & purification; Fundamental and applied biological sciences. Psychology; Genes, Immunoglobulin; Genic rearrangement. Recombination. Transposable element; Humans; Immunoglobulin Heavy Chains - genetics; Lymphoma - genetics; Models, Genetic; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Multigene Family; Oligodeoxyribonucleotides; Oncogenes; Polymerase Chain Reaction - methods; Recombination, Genetic; Sequence Homology, Nucleic Acid; Translocation, Genetic; Chromosomal aberration; Human; Breakpoint; Recombination; Consensus sequence; DNA; Abnormal chromosome; Onc gene; Localization; Chromosome translocation
• ISSN: 0022-1007; 1540-9538
• DOI: 10.1084/jem.175.6.1575

Examination of 64 translocations involving the major breakpoint region (mbr) of the BCL2 oncogene and the immunoglobulin heavy chain locus identified three short (14, 16, and 18 bp) segments within the mbr at which translocations occurred with very high frequency. Each of these clusters was associated with a 15-bp region of sequence homology, the principal one containing an octamer related to chi, the procaryotic activator of recombination. The presence of short deletions and N nucleotide additions at the breakpoints, as well as involvement of JH and DH coding regions, suggested that these sequences served as signals capable of interacting with the VDJ recombinase complex, even though no homology with the traditional heptamer/spacer/nonamer (IgRSS) existed. Furthermore, the BCL2 signal sequences were employed in a bidirectional fashion and could mediate recombination of one mbr region with another. Segments homologous to the BCL2 signal sequences flanked individual members of the XP family of diversity gene segments, which were themselves highly overrepresented in the reciprocal products (18q-) of BCL2 translocation. We propose that the chi-like signal sequences of BCL2 represent a distinct class of recognition sites for the recombinase complex, responsible for initiating interactions between regions of DNA separated by great distances, and that BCL2 translocation begins by a recombination event between mbr and DXP chi signals. Since recombinant joints containing chi, not IgRSS, occur in brain cells expressing RAG-1 (Matsuoka, M., F. Nagawa, K. Okazaki, L. Kingsbury, K. Yoshida, U. Muller, D. T. Larue, J. A. Winer, and H. Sakano. 1991. Science [Wash. DC]. 254:81; reference 1), we further suggest that the product of this gene could mediate both BCL2 translocation and the first step of normal DJ assembly through the creation of chi joints, rather than signal or coding joints.