Brown A M
Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030.
J Membr Biol. 1993 Jan;131(2):93-104. doi: 10.1007/BF02791318.
Ion channels are signaling molecules and by themselves perform no work. In this regard they are unlike the usual membrane enzyme effectors for G proteins. The pathways of G protein receptor, G protein and ion channels are, therefore, purely informational in function. Because a single G protein may have several ion channels as effectors, the effects should be coordinated and this seems to be the case. Inhibition of Ca2+ current and stimulation of K+ currents would have a greater impact than either alone. Additional flexibility is provided by spontaneous noise in the complexes of G protein receptor, G protein, and ion channel. By having a non-zero setpoint, the range of control is extended and the responses become bi-directional.
离子通道是信号分子，自身并不执行任何功。在这方面，它们不同于通常作为G蛋白膜酶效应器的分子。因此，G蛋白受体、G蛋白和离子通道的途径在功能上纯粹是信息性的。由于单个G蛋白可能有多个离子通道作为效应器，这些效应应该是协同的，似乎确实如此。抑制Ca2+电流和刺激K+电流比单独任何一种情况都有更大的影响。G蛋白受体、G蛋白和离子通道复合物中的自发噪声提供了额外的灵活性。通过设定一个非零的设定点，控制范围得以扩展，反应变得双向。
