title: Cloning and structural analysis of cDNAs for bcl-2 and a hybrid bcl-2/immunoglobulin transcript resulting from the t(14;18) translocation.
abstract: cDNAs for the bcl-2 mRNA were cloned from a human common acute lymphoblastic leukemia cell line. Nucleotide sequence analyses showed that the 6 kb bcl-2 mRNA potentially encodes a 26 kd protein that is homologous to a predicted Epstein-Barr virus protein. Most t(14;18) translocation breakpoints cluster within a narrow region of a 5.4 kb exon that contains a long 3'-untranslated region of the bcl-2 mRNA. As a result of t(14;18) translocation, hybrid bcl-2/immunoglobulin heavy chain transcripts are produced that consist of the 5' half of the bcl-2 mRNA fused to a "decapitated" immunoglobulin heavy chain mRNA. Nucleotide sequence analyses confirmed that the hybrid transcripts continue to encode a normal bcl-2 protein. Our results suggest that t(14;18) translocations alter expression of the bcl-2 gene both by transcriptional activation and by abnormal posttranscriptional regulation of bcl-2 mRNA.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002460:Cell Line; D002883:Chromosomes, Human, Pair 14 / Q000648:ultrastructure*; D002887:Chromosomes, Human, Pair 18 / Q000648:ultrastructure*; D004247:DNA / Q000235:genetics*; D005796:Genes; D004854:Herpesvirus 4, Human / Q000235:genetics; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007945:Leukemia, Lymphoid / Q000235:genetics*; D011061:Poly A / Q000032:analysis; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D014178:Translocation, Genetic; D014764:Viral Proteins / Q000235:genetics
chemical_list: D007143:Immunoglobulin Heavy Chains; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D014764:Viral Proteins; D011061:Poly A; D004247:DNA