Chimeric transcripts with an open reading frame are generated as a result of translocation to the Pvt-1 region in mouse B-cell tumors.
Some mouse plasmacytomas exhibit a t(6;15) chromosomal translocation in which the breakpoint resides within the Pvt-1 locus located 260 kilobases (kb) downstream of c-myc on mouse chromosome 15. In this report, we show that the Pvt-1 locus does not exhibit allelic exclusion in that Pvt-1 transcripts continue to be expressed from the non-translocated allele in t(6;15) plasmacytomas. From the translocated allele, we find chimeric transcripts containing a short 57-bp segment of Pvt-1 (termed Pvt-1a) spliced directly to the immunoglobulin constant region sequence (Ig-Ck). These short transcripts have replaced a Jk segment with a trytophan residue via RNA splicing and contain a continuous open reading frame (ORF) from Pvt-1a through Ck. Since this Pvt-1a/Ck transcript is found in all 3 t(6;15) plasmacytomas examined, regardless of the location of the chromosomal breakpoint, we suggest that the Pvt-1a/Ck chimera may have a functional role in the development of mouse plasmacytomas.
Huppi
K
K
Molecular Genetics Section, NCI/NIH, Bethesda, MD 20892.
Siwarski
D
D
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016259:Genes, myc; D007127:Immunoglobulin Constant Regions; D007136:Immunoglobulins / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D050506:Mutant Chimeric Proteins; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism*; D016366:Open Reading Frames / Q000235:genetics*; D010954:Plasmacytoma / Q000235:genetics* / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011993:Recombinant Fusion Proteins / Q000235:genetics* / Q000378:metabolism*; D014178:Translocation, Genetic / Q000235:genetics*; D014407:Tumor Cells, Cultured
D007127:Immunoglobulin Constant Regions; D007136:Immunoglobulins; D050506:Mutant Chimeric Proteins; D009363:Neoplasm Proteins; D011993:Recombinant Fusion Proteins; C090895:chimeric Pvt-1a Ig-Ck