The goal of this work is to develop a detailed understanding of the structure and function of the c-myc gene product. The working hypothesis is that the c-myc protein is involved in the control of transcription and functions as part of a complex of proteins which bind to DNA. The intention is to use a combination of monoclonal antibody and recombinant DNA techniques to analyze the structure and function of this oncogene protein. A panel of epitope specific antibodies will be produced and characterized. These antibodies will be used to define epitopes on the surface of the protein, and regions of the molecule involved in interactions with DNA and with other proteins. Coprecipitation will be used in an attempt to detect proteins associated with c-myc. The antibodies will also be used to determine if there is structural homology between the c-myc protein and other proteins particularly those with known functions or others that bind DNA. In parallel with this work an assay for the biological activity of the c-myc will be developed based on either the transformation of primary lymphocytes or fibroblasts. This assay will then be used to evaluate the effects of site-directed mutagenesis on specific c- myc epitopes. The epitope specific antibodies will be assayed for their effects on the growth of cells into which they are incorporated by microinjection or electroporation. A long term goal is to understand the detailed structure and function of the c- myc protein. This may possibly lead to the ability to specifically modulate the activity of this protein that apparently plays an important role in the control of cell proliferation.