Rose Adam J, Hargreaves Mark
Centre for Physical Activity and Nutrition, School of Health Sciences, Deakin University, Burwood, Australia 3125.
J Physiol. 2003 Nov 15;553(Pt 1):303-9. doi: 10.1113/jphysiol.2003.054171. Epub 2003 Oct 17.
There is evidence in rodents that Ca2+-calmodulin-dependent protein kinase II (CaMKII) activity is higher in contracting skeletal muscle, and this kinase may regulate skeletal muscle function and metabolism during exercise. To investigate the effect of exercise on CaMKII in human skeletal muscle, healthy men (n = 8) performed cycle ergometer exercise for 40 min at 76 +/- 1% peak pulmonary O2 uptake (VO2peak), with skeletal muscle samples taken at rest and after 5 and 40 min of exercise. CaMKII expression and activities were examined by immunoblotting and in vitro kinase assays, respectively. There were no differences in maximal (+ Ca2+, CaM) CaMKII activity during exercise compared with rest. Autonomous (- Ca2+, CaM) CaMKII activity was 9 +/- 1% of maximal at rest, remained unchanged at 5 min, and increased to 17 +/- 1% (P < 0.01) at 40 min. CaMKII autophosphorylation at Thr287 was 50-70% higher during exercise, with no differences in CaMKII expression. The effect of maximal aerobic exercise on CaMKII was also examined (n = 9), with 0.7- to 1.5-fold increases in autonomous CaMKII activity, but no change in maximal CaMKII activity. CaMKIV was not detected in human skeletal muscle. In summary, exercise increases the activity of CaMKII in skeletal muscle, suggesting that it may have a role in regulating skeletal muscle function and metabolism during exercise in humans.
在啮齿动物中有证据表明，钙调蛋白依赖性蛋白激酶II（CaMKII）在收缩的骨骼肌中的活性较高，并且这种激酶可能在运动过程中调节骨骼肌的功能和代谢。为了研究运动对人骨骼肌中CaMKII的影响，8名健康男性在76±1%的峰值肺氧摄取量（VO2peak）下进行了40分钟的自行车测力计运动，在休息时以及运动5分钟和40分钟后采集骨骼肌样本。分别通过免疫印迹和体外激酶测定来检测CaMKII的表达和活性。与休息时相比，运动期间最大（+Ca2+，CaM）CaMKII活性没有差异。自主（-Ca2+，CaM）CaMKII活性在休息时为最大活性的9±1%，在5分钟时保持不变，在40分钟时增加到17±1%（P<0.01）。运动期间Thr287位点的CaMKII自磷酸化水平高50 - 70%，CaMKII表达没有差异。还研究了最大有氧运动对CaMKII的影响（n = 9），自主CaMKII活性增加了0.7至1.5倍，但最大CaMKII活性没有变化。在人骨骼肌中未检测到CaMKIV。总之，运动增加了骨骼肌中CaMKII的活性，表明它可能在调节人类运动期间的骨骼肌功能和代谢中发挥作用。
