Exercise rapidly increases eukaryotic elongation factor 2 phosphorylation in skeletal muscle of men
Exercise rapidly increases eukaryotic elongation factor 2 phosphorylation in skeletal muscle of men
复制标题
运动迅速增加男性骨骼肌真核伸长因子 2 磷酸化
DOI：
10.1113/jphysiol.2005.097154
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
B. Kiens
中科院分区：
文献类型：
--
作者：
A. Rose;C. Broholm;Kristian Kiillerich;S. G. Finn;C. Proud;M. Rider;E. Richter;B. Kiens
众所周知，骨骼肌在收缩过程中蛋白质合成减少，但潜在的调节机制尚不清楚。在这里，我们研究了运动对骨骼肌真核细胞延伸因子2(EEF2)磷酸化的影响，eEF2是蛋白质翻译机制中的关键组成部分。8名健康男性在自行车功率计上进行运动，负荷为∼67%的峰值肺耗氧量，并在安静时以及运动1、10、30、60和90分钟后从股外侧肌取骨骼肌活组织切片。作为对运动的反应，在持续运动90分钟的情况下，Thr56的eEF2磷酸化迅速(即1分钟)增加了5到7倍。骨骼肌eEF2激酶的体外活性不受运动的影响，表明eEF2对eEF2的活性增加不是由共价机制介导的。为了支持这一点，AMPK活性的增加在时间上与eEF2磷酸化无关。然而，骨骼肌eEF2激酶在体外被钙-钙调蛋白有效地激活，这表明工作骨骼肌中较高的eEF2磷酸化是通过钙调素通过钙信号对eEF2激酶的变构激活介导的。鉴于eEF2的磷酸化抑制了eEF2的活性和mRNA的翻译，这些发现表明，收缩骨骼肌中蛋白质合成的抑制是由于钙离子诱导的eEF2激酶的刺激。
Protein synthesis in skeletal muscle is known to decrease during contractions but the underlying regulatory mechanisms are unknown. Here, the effect of exercise on skeletal muscle eukaryotic elongation factor 2 (eEF2) phosphorylation, a key component in protein translation machinery, was examined. Eight healthy men exercised on a cycle ergometer at a workload eliciting ∼67% peak pulmonary oxygen consumption with skeletal muscle biopsies taken from the vastus lateralis muscle at rest as well as after 1, 10, 30, 60 and 90 min of exercise. In response to exercise, there was a rapid (i.e. < 1 min) 5‐ to 7‐fold increase in eEF2 phosphorylation at Thr56 that was sustained for 90 min of continuous exercise. The in vitro activity of skeletal muscle eEF2 kinase was not altered by exercise indicating that the increased activity of eEF2 kinase to eEF2 is not mediated by covalent mechanisms. In support of this, the increase in AMPK activity was temporally unrelated to eEF2 phosphorylation. However, skeletal muscle eEF2 kinase was potently activated by Ca2+–calmodulin in vitro, suggesting that the higher eEF2 phosphorylation in working skeletal muscle is mediated by allosteric activation of eEF2 kinase by Ca2+ signalling via calmodulin. Given that eEF2 phosphorylation inhibits eEF2 activity and mRNA translation, these findings suggest that the inhibition of protein synthesis in contracting skeletal muscle is due to the Ca2+‐induced stimulation of eEF2 kinase.
DOI：
--
发表时间：
2002
期刊：
--
影响因子：
--
作者：
S. Kimball;P. Farrell;L. Jefferson
通讯作者：
S. Kimball;P. Farrell;L. Jefferson
Ca2 和离子载体 A23187 对完整兔网织红细胞蛋白质合成的影响。
DOI：
10.1016/0020-711x(87)90055-3
发表时间：
1991
期刊：
The International journal of biochemistry
影响因子：
--
作者：
Wong,WL;Brostrom,MA;Brostrom,CO
通讯作者：
Brostrom,CO