Rose Adam J, Frøsig Christian, Kiens Bente, Wojtaszewski Jørgen F P, Richter Erik A
Copenhagen Muscle Research Centre, Department of Exercise and Sport Sciences, Section of Human Physiology, University of Copenhagen, Universitetsparken 13, Copenhagen, Denmark 2100.
J Physiol. 2007 Sep 1;583(Pt 2):785-95. doi: 10.1113/jphysiol.2007.138529. Epub 2007 Jul 12.
Here the hypothesis that skeletal muscle Ca(2+)-calmodulin-dependent kinase II (CaMKII) expression and signalling would be modified by endurance training was tested. Eight healthy, young men completed 3 weeks of one-legged endurance exercise training with muscle samples taken from both legs before training and 15 h after the last exercise bout. Along with an approximately 40% increase in mitochondrial F(1)-ATP synthase expression, there was an approximately 1-fold increase in maximal CaMKII activity and CaMKII kinase isoform expression after training in the active leg only. Autonomous CaMKII activity and CaMKII autophosphorylation were increased to a similar extent. However, there was no change in alpha-CaMKII anchoring protein expression with training. Nor was there any change in expression or Thr(17) phosphorylation of the CaMKII substrate phospholamban with training. However, another CaMKII substrate, serum response factor (SRF), had an approximately 60% higher phosphorylation at Ser(103) after training, with no change in SRF expression. There were positive correlations between the increases in CaMKII expression and SRF phosphorylation as well as F(1)ATPase expression with training. After training, there was an increase in cyclic-AMP response element binding protein phosphorylation at Ser(133), but not expression, in muscle of both legs. Taken together, skeletal muscle CaMKII kinase isoform expression and SRF phosphorylation is higher with endurance-type exercise training, adaptations that are restricted to active muscle. This may contribute to greater Ca(2+) mediated regulation during exercise and the altered muscle phenotype with training.
在此，我们对耐力训练是否会改变骨骼肌钙调蛋白依赖性激酶II（CaMKII）的表达和信号传导这一假设进行了测试。八名健康的年轻男性完成了为期3周的单腿耐力运动训练，在训练前以及最后一次运动 bout 后15小时从双腿采集肌肉样本。随着线粒体F(1)-ATP合酶表达增加约40%，仅在运动腿训练后，最大CaMKII活性和CaMKII激酶亚型表达增加了约1倍。自主CaMKII活性和CaMKII自身磷酸化程度也有类似增加。然而，训练后α-CaMKII锚定蛋白表达没有变化。训练后，CaMKII底物受磷蛋白的表达或苏氨酸(17)磷酸化也没有任何变化。然而，另一种CaMKII底物血清反应因子（SRF）在训练后其丝氨酸(103)处的磷酸化水平提高了约60%，而SRF表达没有变化。CaMKII表达增加与SRF磷酸化以及训练后F(1)ATP酶表达增加之间存在正相关。训练后，双腿肌肉中环状AMP反应元件结合蛋白在丝氨酸(133)处的磷酸化增加，但表达没有增加。综上所述，耐力型运动训练后骨骼肌CaMKII激酶亚型表达和SRF磷酸化水平更高，这些适应性变化仅限于运动的肌肉。这可能有助于运动期间钙(2+)介导的调节增强以及训练后肌肉表型的改变。
