Chlorpromazine binding to the PAS domains uncovers the effect of ligand modulation on EAG channel activity.
Chlorpromazine binding to the PAS domains uncovers the effect of ligand modulation on EAG channel activity.
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氯丙嗪与 PAS 结构域的结合揭示了配体调节对 EAG 通道活性的影响。
DOI：
10.1074/jbc.ra119.012377
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Brelidze,TinatinI
中科院分区：
文献类型：
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作者：
Wang,Ze-Jun;Soohoo,StephanieM;Tiwari,PurushottamB;Piszczek,Grzegorz;Brelidze,TinatinI
Ether-a-go-go（EAG）钾选择性通道是神经元兴奋性和癌症进展的主要调节因子。EAG通道在其细胞内N-末端区域含有Per-Arnt-Sim（PAS）结构域。PAS结构域在结构上类似于非离子通道蛋白中的PAS结构域，其中这些结构域经常充当配体结合结构域。尽管结构相似，但尚不清楚PAS结构域是否可以通过配体结合来调节EAG通道功能。在这里，使用表面等离子体共振，色氨酸荧光，并记录inXenopus laevisocytes的EAG电流分析，我们表明，一个小分子氯丙嗪（CH），广泛用作抗精神病药物，绑定到孤立的PAS结构域的EAG通道，并抑制这些通道的电流。缺乏PAS结构域的突变体EAG通道显示CH的抑制显著降低，表明CH直接通过与PAS结构域的结合来影响来自EAG通道的电流。我们的研究支持了这一假设，即在EAG通道门控中存在以前未考虑的步骤，这些步骤可以通过与PAS结构域结合的配体激活。这对于理解EAG和相关ERG和ELK K+通道的门控机制具有广泛的意义，并将PAS结构域作为EAG和相关通道中药物发现的新靶点。EAG通道活性的上调与癌症和神经系统疾病有关。我们的研究提出了将抗精神病药物氯丙嗪用于治疗神经系统疾病和癌症的可能性。
Ether-a-go-go (EAG) potassium selective channels are major regulators of neuronal excitability and cancer progression. EAG channels contain a Per–Arnt–Sim (PAS) domain in their intracellular N-terminal region. The PAS domain is structurally similar to the PAS domains in non-ion channel proteins, where these domains frequently function as ligand-binding domains. Despite the structural similarity, it is not known whether the PAS domain can regulate EAG channel function via ligand binding. Here, using surface plasmon resonance, tryptophan fluorescence, and analysis of EAG currents recorded inXenopus laevisoocytes, we show that a small molecule chlorpromazine (CH), widely used as an antipsychotic medication, binds to the isolated PAS domain of EAG channels and inhibits currents from these channels. Mutant EAG channels that lack the PAS domain show significantly lower inhibition by CH, suggesting that CH affects currents from EAG channels directly through the binding to the PAS domain. Our study lends support to the hypothesis that there are previously unaccounted steps in EAG channel gating that could be activated by ligand binding to the PAS domain. This has broad implications for understanding gating mechanisms of EAG and related ERG and ELK K+channels and places the PAS domain as a new target for drug discovery in EAG and related channels. Up-regulation of EAG channel activity is linked to cancer and neurological disorders. Our study raises the possibility of repurposing the antipsychotic drug chlorpromazine for treatment of neurological disorders and cancer.