DESCRIPTION:(Adapted from the Investigator's abstract): The adenovirus E1A protein induces imortalization and transformation of cells in culture and is therefore an excellent model for the study of cellular transformation. E1A binds specific cell proteins including the retinoblastoma protein (Rb) and p300/CBP proteins that control transcription, in part, by altering chromatin structure. E1A inhibits the function of the chromatin remodeling complex SWI/SNF, which interacts with Rb protein and possibly p300. Specific aim 1 proposes to define and characterize the mammalian SWI/SNF complex with respect to its role in regulation of transcription. It will be determined how the complex inhibits c-fos expression at the transcriptional level. The structural changes that accompany the inhibition of c-fos gene activity will be characterized, and assays will be developed to measure the physical association of SWI/SNF with specific mammalian promoters in vivo. Studies will characterize the effects of E1A on SWI/SNF processes. Specific aim 2 will use a yeast genetic approach to understand E1A inhibition of the SWI/SNF complex. The yeast proteins that interact with E1A will be identified and their influence on E1A activity will be determined. Similar studies will then be conducted in mammalian cells using the information gained from the yeast system.