| Abstract: |
The bic locus is a common retroviral integration site in avian leukosis virus (ALV)-induced B-cell lymphomas originally identified by infection of chickens with ALVs of two different subgroups (Clurman and Hayward, Mol. Cell. Biol. 9:2657-2664, 1989). Based on its frequent association with c-myc activation and its preferential activation in metastatic tumors, the bic locus is thought to harbor a gene that can collaborate with c-myc in lymphomagenesis and presumably plays a role in late stages of tumor progression. In the present study, we have cloned and characterized two novel genes, bdw and bic, at the bic locus, bdw encoded a putative novel protein of 345 amino acids. However, its expression did not appear to be altered in tumor tissues, suggesting that it is nut involved in oncogenesis. The bic gene consisted of two exons and was expressed as two spliced and alternatively polyadenylated transcripts at low levels in lymphoid/hematopoietic tissues. In tumors harboring bic integrations, proviruses drove bic gene expression by promoter insertion, resulting in high levels of expression of a chimeric RNA containing bic exert 2. Interestingly, bic lacked an extensive open reading frame, implying that it may function through its RNA. Computer analysis of RNA from small exon 2 of bic predicted extensive double-stranded structures, including a highly ordered RNA duplex between nucleotides 316 and 461. The possible role of bic in cell growth and differentiation is discussed in view of the emerging evidence that untranslated RNAs play a role in growth control. |
| Keywords: |
promoter region; exon; exons; nonhuman; proteins; animal cell; animals; animal tissue; genes; gene expression; gene locus; avian leukosis oncovirus; animalia; avian leukosis virus; molecular cloning; cloning, molecular; gene expression regulation, developmental; aves; b cell lymphoma; gene activation; gene expression regulation, neoplastic; lymphoma, b-cell; amino acid sequence; molecular sequence data; rna, messenger; organ specificity; alternative rna splicing; base sequence; nucleic acid conformation; gene insertion; rna, neoplasm; rna splicing; complementary dna; double stranded rna; virus carcinogenesis; sequence analysis, dna; chickens; open reading frames; restriction mapping; promoter regions (genetics); virus dna cell dna interaction; virus integration; avian proteins; polyadenylated rna; priority journal; article; gallus gallus; provirus; oncovirinae; leukosis virus
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