Global Phosphoproteomic Analysis of Human Skeletal Muscle Reveals a Network of Exercise-Regulated Kinases and AMPK Substrates
Exercise is essential in regulating energy metabolism and whole-body insulin sensitivity. To explore the exercise signaling network, we undertook a global analysis of protein phosphorylation in human skeletal muscle biopsies from untrained healthy males before and after a single high-intensity exercise bout, revealing 1,004 unique exercise-regulated phosphosites on 562 proteins. These included substrates of known exercise-regulated kinases (AMPK, PKA, CaMK, MAPK, mTOR), yet the majority of kinases and substrate phosphosites have not previously been implicated in exercise signaling. Given the importance of AMPK in exercise-regulated metabolism, we performed a targeted in vitro AMPK screen and employed machine learning to predict exercise-regulated AMPK substrates. We validated eight predicted AMPK substrates, including AKAP1, using targeted phosphoproteomics. Functional characterization revealed an undescribed role for AMPK-dependent phosphorylation of AKAP1 in mitochondrial respiration. These data expose the unexplored complexity of acute exercise signaling and provide insights into the role of AMPK in mitochondrial biochemistry.
|ISBN||1932-7420 (Electronic) 1550-4131 (Linking)|
|Authors||Hoffman, N. J. ; Parker, B. L. ; Chaudhuri, R. ; Fisher-Wellman, K. H. ; Kleinert, M. ; Humphrey, S. J. ; Yang, P. ; Holliday, M. ; Trefely, S. ; Fazakerley, D. J. ; Stockli, J. ; Burchfield, J. G. ; Jensen, T. E. ; Jothi, R. ; Kiens, B. ; Wojtaszewski, J. F. ; Richter, E. A. ; James, D. E.;|
|Responsible Garvan Author||(missing name)|
|Publisher Name||Cell Metabolism|
|URL link to publisher's version||http://www.ncbi.nlm.nih.gov/pubmed/26437602|
|OpenAccess link to author's accepted manuscript version||https://publications.gimr.garvan.org.au/open-access/13188|