High-Intensity Interval Training Remodels the Proteome and Acetylome of Human Skeletal Muscle

Abstract

Exercise is an effective strategy in the prevention and treatment of metabolic diseases. Alterations in the skeletal muscle proteome, including post-translational modifications, regulate its metabolic adaptations to exercise. Here, we examined the effect of high-intensity interval training (HIIT) on the proteome and acetylome of human skeletal muscle, revealing the response of 3168 proteins and 1263 lysine acetyl-sites on 464 acetylated proteins. We identified global protein adaptations to exercise training involved in metabolism, excitation-contraction coupling, and myofibrillar calcium sensitivity. Furthermore, HIIT increased the acetylation of mitochondrial proteins, particularly those of complex V, likely via non-enzymatic mechanisms. We also highlight the regulation of exercise-responsive histone acetyl-sites. These data demonstrate the plasticity of the skeletal muscle proteome and acetylome, providing insight into the regulation of contractile, metabolic and transcriptional processes within skeletal muscle. Herein, we provide a substantial hypothesis-generating resource to stimulate further mechanistic research investigating how exercise improves metabolic health.

Divergent serum metabolomic, skeletal muscle signaling, transcriptomic, and performance adaptations to fasted versus whey protein-fed sprint interval training

“…Recent research has found no effect of acute endurance exercise on human skeletal muscle pan-acetylation status ( 95 ). Other authors observed an increase in the expression of SIRT deacetylases over accumulated bouts of HIIT ( 96 ), which are known to exert regulatory effects on mitochondrial fatty acid oxidation and other metabolic processes ( 24 ). Evidence indicates that almost all proteins involved in skeletal muscle contraction are acetylated, and the subcellular component where lysine acetylation is most prominent is the mitochondria, with 63% of proteins containing acetylation sites ( 25 , 97 ).…”

Post-translational Modifications: The Signals at the Intersection of Exercise, Glucose Uptake, and Insulin Sensitivity

“…In spite of mitochondrial acetylation being linked to insulin resistance ( 197 , 214-216 ), we have shown that 5 weeks of high-intensity interval training increases acetylation within human skeletal muscle, predominantly within the mitochondria ( 195 ). Furthermore, increased acetylation of PDH E1a on Lys 336 was within the top 5 most regulated acetyl sites with exercise training ( 195 ). As exercise training increases insulin sensitivity ( 11-16 ), elevated acetylation within skeletal muscle is unlikely to cause insulin resistance.…”

“…Initially identified on histones, acetylation is pervasive across the proteome. In skeletal muscle, mitochondrial proteins, in particular those of the tricarboxylic cycle and the electron transport chain, make up the majority of acetylated proteins and also show elevated acetylation stoichiometry ( 194 , 195 ). Furthermore, acetylation is sensitive to the cellular energetic state ( 196 , 197 ), potentially linking metabolic flux to protein function and enzyme activity.…”

“…Furthermore, insulin reduces the acetylation of AKT in skeletal muscle of fasted, but not fed, mice ( 200 ). However, acetylated peptides from proteins within the insulin signaling pathways have mostly been undetectable via mass spectrometry-based proteomics performed in rat and human skeletal muscle ( 194 , 195 ), which might reflect technical challenges in their enrichment or their low abundance/absence. Conversely, proteins involved in glycolysis are abundantly acetylated within skeletal muscle ( 194 , 195 ).…”

“…Furthermore, while the functional implications of canonical post-translational modifications in insulin- and exercise-sensitive signaling cascades are typically well characterized (for example phosphorylation on AKT Thr 308 and Ser 473, AMPK Thr172, and CAMKII Thr 286), little is known about the majority of insulin- and exercise-sensitive post-translational modifications. Exercise alone regulates over 1000 phospho-sites, nearly 400 ubiquitin-sites, and nearly 300 acetyl-sites ( 108 , 184 , 195 ). To truly understand how insulin and exercise induce glucose uptake in skeletal muscle, it is important to expand the understanding of the functional roles of post-translational modifications over and above canonical sites.…”