Functional effects of protein kinases and peroxynitrite on cardiac carnitine palmitoyltransferase-1 in isolated mitochondria
Functional effects of protein kinases and peroxynitrite on cardiac carnitine palmitoyltransferase-1 in isolated mitochondria
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DOI：
10.1007/s11010-009-0303-2
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发表时间：
2010-04-01
影响因子：
4.3
通讯作者：
McNeill, John H.
中科院分区：
文献类型：
--
作者：
Sharma, Vijay;Abraham, Thomas;McNeill, John H.
我们之前的研究表明，美托洛尔可以抑制肉碱棕榈酰基转移酶-1的催化活性，并在30分钟内降低其丙二酰辅酶a的敏感性，这表明共价修饰的重要性。本研究的目的是表征ptm对心脏CPT-1的影响。从雄性Wistar大鼠的心脏中分离线粒体，用感兴趣的激酶（蛋白激酶A、CAMK-II、p38 MAPK、Akt）或过氧亚硝酸盐和硝普钠孵育。PKA降低了CPT-1丙二酰辅酶a的敏感性，这与CPT-1A的磷酸化有关，而CAMK-II通过磷酸化CPT-1B增加了丙二酰辅酶a的敏感性。p38结合CPT-1B并刺激CPT-1活性。CPT-1与这些激酶及其支架蛋白的关联在共定位研究中得到证实。过氧亚硝酸盐和硝普钠可逆地刺激CPT-1活性，而CPT-1B活性的变化与CPT-1B的谷胱甘肽化最为一致。这些研究发现了一个新的激酶、支架蛋白和硫醇氧化还原化学调控系统，可以在体外控制心脏CPT-1。
We have previously shown that metoprolol can inhibit carnitine palmitoyltransferase-1 catalytic activity and decrease its malonyl CoA sensitivity within 30 min, suggesting the importance of a covalent modification. The aim of this study was to characterize the effects of PTMs on CPT-1 in the heart. Mitochondria were isolated from the hearts of male Wistar rats and incubated with kinases of interest (protein kinase A, CAMK-II, p38 MAPK, Akt) or with peroxynitrite and sodium nitroprusside. PKA decreased CPT-1 malonyl CoA sensitivity, associated with phosphorylation of CPT-1A, whereas CAMK-II increased malonyl CoA sensitivity by phosphorylating CPT-1B. p38 bound to CPT-1B and stimulated CPT-1 activity. The association of CPT-1 with these kinases and their scaffolding proteins was confirmed in co-localization studies. Peroxynitrite and sodium nitroprusside reversibly stimulated CPT-1 activity, and the change in CPT-1B activity was most consistently associated with glutathiolation of CPT-1B. These studies have identified a new regulatory system of kinases, scaffolding proteins and thiol redox chemistry which can control cardiac CPT-1 in vitro.