Summary Given the importance of physical activity in healthy living and prevention and treatment of many diseases, it is not surprising that determining the molecular mechanisms or “map” of the exercise response has become an important focus of biomedical research. The Molecular Transducers of Physical Activity in Humans Consortium (MoTrPAC) is a multicenter consortium that is currently being designed to achieve this important goal. The UF PASS Phase 2 experiments have been focused on two goals. The first has been to develop the use of a new method to support the discovery of factors released from muscle during exercise. The tool is the TurboID enzyme that can label proteins in close proximity with a biotin moiety. With this labeling we can selectively extract proteins derived from skeletal muscle with streptavidin beads from other peripheral tissues and blood. The second goal of our Phase 2 experiments is focused on direct determination of transcription factors within the nucleus following acute exercise to support the known changes in gene expression. To approach this challenge, we have optimized isolation of nuclei from tissue, starting with muscle tissue. We have identified enriched clusters of proteins that are associated with transcription, RNA processing and chromatin remodeling that provide insight in the muscle changes. For this supplement, we would like to take these studies to publication with inclusion of additional tissues such as liver, kidney and colon. We have proposed the following three specific aims with associated manuscripts: Specific Aim 1. To develop the TurboID methodology for discover of proteins released from muscle at 4 and 24hrs following an acute bout of exercise. Manuscript 1 Specific Aim 2. To define the nuclear proteome changes with acute exercise in liver, lung and muscle at immediate post exercise and 1hr post exercise. Identify novel pathways discovered with this approach, map targeted transcription factor changes coupled with gene expression with deep RNA sequencing. Manuscript 2 Specific Aim 3. To write, at least one other manuscript using MoTrPAC PASS data already available. One plan is to focus on the acute transcriptional response to exercise data in muscle, and other tissues to define common and unique genomic and transcriptomic responses.