The post-genomic flood of genetic sequence information has already begun, and perhaps the largest task ahead is to place the myriads of newly-discovered biomolecules into functional context. The next generation of tools for genomic and proteomic analysis must work non-invasively and within the native cellular context. Capitalizing on recent advances in fluorescence technology and biopolymer engineering, this proposal describes three new generalizable methods for measuring RNA and protein function inside the living cell. The specific aims are: (1) Development of genetically-encoded fluorescent reporters of enzyme activity in living cells. Specific application to the detection of histone kinase, acetyltransferase, and methyltransferase activities. (2) Development of ribozyme-based reporters for the detection of endogenous gene expression and endogenous protein-protein interactions in living cells. (3) Evolution of artificial enzymes for the site-specific labeling of proteins in living cells. The advantages offered by these methodologies over existing tools are two-fold: (a) minimally invasive applicability to any live cell culture rather than purified samples or heterologous systems, and (b) except for the site-specific labeling strategy described in Specific Aim 3, applicability to native genes and proteins, rather than fused reporter constructs. [unreadable] [unreadable] This research will be implemented by an investigator trained in chemical and biological techniques ranging from organic synthesis to molecular biology to live mammalian cell imaging. The investigator will develop a team of graduate students and postdoctoral researchers interested in working at the biology-chemistry interface to address long-standing biological problems on a genome-wide scale with molecular techniques. The chances of success will be maximized by execution of the proposed research in a chemistry department at a major research university. [unreadable] [unreadable]