Campbell V, Berrow N, Brickley K, Page K, Wade R, Dolphin A C
Department of Pharmacology, Royal Free Hospital School of Medicine, London, UK.
FEBS Lett. 1995 Aug 14;370(1-2):135-40. doi: 10.1016/0014-5793(95)00813-o.
The dihydropyridine-sensitive calcium channel agonist (-)-BayK 8644 was found to produce an enhancement of the intrinsic hydrolysis of GTP by Go in rat frontal cortex membranes. An anti-calcium channel beta-subunit antiserum abolished the (-)-BayK 8644-stimulated hydrolysis of GTP by Go and reduced the dihydropyridine binding capacity of the cortical membranes. A peptide which mimics the beta-subunit binding domain of the calcium channel complex, also attenuated (-)-BayK 8644 activation of GTPase. This study suggests that the calcium channel beta-subunit is the principal component of the channel complex involved in linking dihydropyridine agonist binding to enhanced hydrolysis of GTP by Go. This may be a mechanism by which calcium channels can normally act to limit the duration of a G-protein modulatory signal.
发现二氢吡啶敏感钙通道激动剂（-）-BayK 8644可增强大鼠额叶皮质膜中Go对GTP的内在水解作用。一种抗钙通道β亚基抗血清消除了（-）-BayK 8644刺激的Go对GTP的水解作用，并降低了皮质膜中二氢吡啶的结合能力。一种模拟钙通道复合物β亚基结合域的肽也减弱了（-）-BayK 8644对GTP酶的激活作用。本研究表明，钙通道β亚基是通道复合物的主要成分，参与将二氢吡啶激动剂结合与Go增强的GTP水解联系起来。这可能是钙通道正常作用以限制G蛋白调节信号持续时间的一种机制。
