Increased atypical PKC activity in endurance-trained human skeletal muscle

Biochem Biophys Res Commun. 2003 Dec 26;312(4):1147-53. doi: 10.1016/j.bbrc.2003.11.041.


Exercise training may modulate protein content and enzyme activities in skeletal muscle. However, it is not known whether atypical protein kinase C (aPKC) is affected by training. Thus, we investigated aPKC, extracellular-regulated protein kinase 1/2 (ERK 1/2), and P38 mitogen-activated protein kinase (P38 MAPK) activities and expression in skeletal muscle from untrained and endurance-trained subjects at rest and after 20min of cycle exercise (80% of VO(2peak)). Activities of aPKC (P<0.05) and ERK 1/2 (P=0.06), but not phosphorylation of P38 MAPK, were higher in trained than in sedentary subjects at rest. Exercise increased the activities of ERK 1/2 (P<0.01) and aPKC (P<0.05) and the phosphorylation (Thr180/Tyr182) of P38 MAPK (P<0.01) similarly in muscle from trained and sedentary subjects. Protein expression of the kinases was similar in trained and sedentary muscle. The increased aPKC activity in exercise-trained subjects could be important in explaining the enhanced insulin action in these individuals.

Publication types

  • Clinical Trial
  • Comparative Study
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Enzyme Activation / physiology
  • Exercise Test
  • Humans
  • Male
  • Mitogen-Activated Protein Kinase 1 / analysis
  • Mitogen-Activated Protein Kinase 1 / physiology*
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases / analysis
  • Mitogen-Activated Protein Kinases / physiology*
  • Muscle, Skeletal / cytology
  • Muscle, Skeletal / physiology*
  • Physical Education and Training / methods
  • Physical Endurance / physiology*
  • Protein Kinase C / analysis
  • Protein Kinase C / physiology*
  • Rest / physiology
  • p38 Mitogen-Activated Protein Kinases


  • PKC-3 protein
  • Protein Kinase C
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases