Acute exercise alters Gαi2 protein expressions through the ubiquitin-proteasome proteolysis pathway in rat adipocytes
Acute exercise alters Gαi2 protein expressions through the ubiquitin-proteasome proteolysis pathway in rat adipocytes
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DOI：
10.1016/j.bbrc.2004.08.202
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发表时间：
2004-10-22
影响因子：
3.1
通讯作者：
Izawa, T
中科院分区：
文献类型：
--
作者：
Ogasawara, J;Sakurai, T;Izawa, T
研究了急性运动对大鼠脂肪细胞异三聚体G蛋白α亚基蛋白表达的影响。Galphai 2蛋白表达在运动后0和3 h显著降低，但在运动后24 h增加，而Galphai 2 mRNA表达无改变。其他α亚基Galphas、Galphai 1和Galphai 3的蛋白表达不受影响。26 S蛋白酶体活性和Galphai 2蛋白的多聚泛素化在运动后0和3 h均显著增加。运动后24 h，蛋白酶体活性降低，Gai 2蛋白的多聚泛素化水平恢复到对照水平。运动后0和3小时的Gai 2蛋白表达的减少完全防止注射蛋白酶体抑制剂或β-肾上腺素能受体阻滞剂运动前。因此，急性运动通过涉及β-肾上腺素能受体与激动剂偶联以及随后的泛素-蛋白酶体依赖性蛋白水解的机制改变了Galpha 12蛋白的表达。(C)2004爱思唯尔公司All rights reserved.
The effects of acute exercise on the protein expressions of heterotrimeric G protein alpha subunits were examined in rat adipocytes. Galphai2 protein expression was significantly reduced 0 and 3 h after exercise but increased 24 h after exercise, without alterations in Galphai2 mRNA expressions. The protein expressions of other alpha subunits, Galphas, Galphai1, and Galphai3, were not influenced. Both the 26S proteasome activity and polyubiquitination of Galphai2 protein were significantly increased 0 and 3 h after exercise. Whereas, proteasome activity was decreased, and the polyubiquitination of Gai2 protein was returned to the control level 24 h after exercise. The reductions in Gai2 protein expressions 0 and 3 h after exercise were completely prevented by the injection either of a proteasome inhibitor or of a beta-adrenergic receptor blocker prior to exercise. Thus, acute exercise altered the expression of Galphai2 protein via mechanisms which involve the coupling of beta-adrenergic receptors to an agonist with subsequent ubiquitin-proteasome-dependent proteolysis. (C) 2004 Elsevier Inc. All rights reserved.