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.;|
|Publisher Name||CELL METAB|
|Published Date||2015-01-01 00:00:00|