The importance of E2A proteins as potent regulators of early B cell formation is well established, but their role in the mature B- to plasma cell transition remains unclear. Recently, a new E2A-containing E-box binding species, designated P-E2A, has been detected during the mature B- to plasma cell transition. The objectives of the research include 1) investigating the transcriptional components and role of the stage-specific E2A-containing complex, P-E2A; 2) identifying other protein(s) that interact with E2A in plasma cells; 3) characterizing these E2A-interacting protein(s). To accomplish these specific goals, protein-protein interactional cloning systems will be performed to delineate the molecular components of P-E2A and other E2A-interacting protein complexes unique to plasma cells. The retrieval of genes encoding potential E2A-interacting proteins will be subsequently analyzed using a broad spectrum of genetic and biochemical techniques, including gene cloning and sequencing, RNA- and immunoblotting, electrophoretic-mobility shift analyses, and DNA transfections in a variety of cultured cells. Other E2A-interacting proteins restricted to cell types distinct from plasma cells have been identified and demonstrated to be important transcriptional regulators of processes such as cellular differentiation and proliferation. This project will determine whether E2A-interacting transcription factors found in plasma cells play a similar role in processes such as plasma cell formation or cell-specific gene expression e.g. antibody gene transcription. The results of these studies will identify transcription factors whose pattern of expression is restricted to the plasma cell lineage and will provide data that will help to elucidate the molecular mechanisms that govern cell-restricted eukaryotic gene expression. E2A proteins are critical transcriptional regulators of the immune system. In particular, E2A gene products are required for the development of specialized cells that synthesize antibodies. This project will enhance the knowledge of E2A-associating proteins and provide insight into how interactions between E2A and various regulatory proteins result in the formation of DNA-protein complexes that regulate antibody production in plasma cells.
