THE BCMA GENE, PREFERENTIALLY EXPRESSED DURING B-LYMPHOID MATURATION,IS BIDIRECTIONALLY TRANSCRIBED

In a previous study of a t(4;16)(q26;p13) translocation, found in a hu man malignant T-cell lymphoma the BCMA gene, located on chromosome ban d 16p13.1, has been characterized. In this study we show that the BCMA gene is organized into three exons and its major initiation transcrip tion site is located 69 nucleotides downstream of a TATA box. RNase pr otection assays demonstrated that the BCMA gene is preferentially expr essed in mature B cells, suggesting a role for this gene in the B-cell developmental process. A cDNA complementary to the BCMA cDNA was clon ed and sequenced and its presence was assessed by RNase protection ass ay and anchor-PCR amplification. This antisense-BCMA RNA is transcribe d from the same locus as BCMA, and exhibits mRNA characteristic featur es, e.g. polyadenylation and splicing. It also contains an ORF encodin g a putative 115 aa polypeptide, presenting no homology with already k nown sequences. RNase protection assays demonstrated the simultaneous expression of natural sense and antisense-BCMA transcripts in the majo rity of human B-cell lines tested.