Project Summary This proposal GM62437 combines the use of chemical approaches, enzymologic analysis, and cellular studies to enhance our understanding of enzymes regulating protein acylation and methylation. It is now well-accepted that post-translational modifications (PTMs) involving lysine acetylation/acylation and reversible methylation on histones and other proteins are central to epigenetics. Such epigenetic modifying enzymes are viewed as attractive drug targets for cancer and other diseases. Although there has been increasing efforts to understand the mechanisms and functions of these PTMs and the enzymes that catalyze them, there are major gaps in our understanding in these areas. Filling these gaps has the potential to provide a clearer understanding of basic biomedical processes and has the opportunity to enhance the development of novel therapeutic approaches and disease diagnostic strategies. There are three Specific Aims in the current proposal: 1) Determine the roles of p300/CBP acetyltransferase activity in cellular pathways. We will develop and employ new chemical tools that target the p300/CBP HAT domain and bromodomain and examine these effects of these on cell growth, protein acetylation, signaling, and gene expression. 2) Elucidate the mechanisms of the LSD1 and HDAC1 activities in the CoREST complex and develop inhibitors of these activities in the CoREST complex. We will employ a purified CoREST complex and semiynethtic nucleosomes in biochemical and structural studies and design small molecule LSD1 and dual action LSD1/HDAC1 inhibitors for cellular studies. 3) Devise methods for the synthesis of acyl-Lys mimics and incorporate these into proteins for enhancing our understanding of acyl-Lys as PTMs. We will use a Cys modification stratgey to introduce hydrazino-Lys acylation mimics into proteins and study their biochemical properties. We believe that this research effort has the potential to greatly expand our knowledge of protein post-translational modification mechanisms and functions and identify new therapeutic opportunities for treating metabolic and neoplastic diseases.