94109067 Zwollo B-cell-specific activating protein (BSAP) is thought to play important roles in the transcriptional regulation of several B-cell-specific genes, including (CD19, CD20, V(pre-B) IgH, Ca, and blk.) BSAP is encoded by the Pax-5 gene, a member of the Pax gene family of homeodomain class transcription factors. In this project, the molecular nature of Pax-5 gene transcripts and proteins will be investigated in mouse spleen and B-cell lines. Preliminary results have revealed that at least two alternative splicing products are present within the murine B-cell population. The presence and structure of those, and any additional alternatively spliced Pax-5 isoforms in vivo will be investigated. To study the structure/function relationships of the different Pax-5 isoforms, the following basic questions will be addressed: 1) What is the structure of the different isoforms? 2) How do the different isoforms effect in vivo transcription? 3) Can the different isoforms interact with their DNA target, the BSAP-binding site? 4) When are the different isoforms present during B-cell development ? 5) Which areas on the Pax-5 isoforms are involved in protein-protein interactions? These studies will increase our understanding of the functional roles that Pax-5 plays during B-cell development, as well as contribute to the elucidation of the mechanisms coordinating cell proliferation and differentiation throughout B-lymphocyte development. %%% B-lymphocytes or B-cells are responsible for producing circulating antibodies in response to antigen stimulation and are an essential component of the immune response. B-cell-specific activating protein (BSAP) is thought to play important roles in the transcriptional regulation of several B-cell-specific genes. BSAP is encoded by the Pax-5 gene, a member of the Pax gene family of homeodomain class transcription factors. In this project, the molecular nature of Pax-5 gene RNA transcripts and proteins will be characterized in mouse spleen and B-cell lines, and the structure/function relationships of the different Pax-5 gene products will be determined. These studies will increase our understanding of the functional roles that Pax-5 plays during B-cell development, as well as contribute to the elucidation of the mechanisms coordinating cell proliferation and differentiation throughout B-lymphocyte development. ***
