1] Department of Physiology and Cellular Biophysics, Columbia University, College of Physicians and Surgeons, 1150 St Nicholas Avenue, New York, New York 10032, USA [2].
Nat Commun. 2013;4:2540. doi: 10.1038/ncomms3540.
Ca(2+) influx via voltage-dependent CaV1/CaV2 channels couples electrical signals to biological responses in excitable cells. CaV1/CaV2 channel blockers have broad biotechnological and therapeutic applications. Here we report a general method for developing novel genetically encoded calcium channel blockers inspired by Rem, a small G-protein that constitutively inhibits CaV1/CaV2 channels. We show that diverse cytosolic proteins (CaVβ, 14-3-3, calmodulin and CaMKII) that bind pore-forming α1-subunits can be converted into calcium channel blockers with tunable selectivity, kinetics and potency, simply by anchoring them to the plasma membrane. We term this method 'channel inactivation induced by membrane-tethering of an associated protein' (ChIMP). ChIMP is potentially extendable to small-molecule drug discovery, as engineering FK506-binding protein into intracellular sites within CaV1.2-α1C permits heterodimerization-initiated channel inhibition with rapamycin. The results reveal a universal method for developing novel calcium channel blockers that may be extended to develop probes for a broad cohort of unrelated ion channels.
钙离子通过电压门控型 CaV1/CaV2 通道流入，将电信号传递到兴奋细胞中的生物反应。CaV1/CaV2 通道阻滞剂在生物技术和治疗方面有广泛的应用。在这里，我们报道了一种受 Rem 启发的开发新型基因编码钙通道阻滞剂的通用方法，Rem 是一种小 G 蛋白，可持续抑制 CaV1/CaV2 通道。我们发现，与孔形成的 α1 亚基结合的多种细胞质蛋白（CaVβ、14-3-3、钙调蛋白和 CaMKII），通过锚定在质膜上，可转化为具有可调选择性、动力学和效力的钙通道阻滞剂。我们将这种方法称为“通过相关蛋白的膜固定化诱导通道失活”（ChIMP）。ChIMP 可能适用于小分子药物发现，因为将 FK506 结合蛋白工程化到 CaV1.2-α1C 的细胞内位点中，可以用雷帕霉素引发异二聚体起始的通道抑制。研究结果揭示了一种开发新型钙通道阻滞剂的通用方法，该方法可能扩展到开发广泛无关的离子通道的探针。
