Title: Structural basis for human Cav1.2 inhibition by multiple drugs and the neurotoxin calciseptine.

Authors: Shuai Gao, Xia Yao, Jiaofeng Chen, Gaoxingyu Huang, Xiao Fan, Lingfeng Xue, Zhangqiang Li, Tong Wu, Yupeng Zheng, Jian Huang, Xueqin Jin, Yan Wang, Zhifei Wang, Yong Yu, Lei Liu, Xiaojing Pan, Chen Song, Nieng Yan

Journal, date & volume: Cell, 2023Nov22, 186, 5363-5374.e16

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/37972591

Abstract
Cav1.2 channels play crucial roles in various neuronal and physiological processes. Here, we present cryo-EM structures of human Cav1.2, both in its apo form and in complex with several drugs, as well as the peptide neurotoxin calciseptine. Most structures, apo or bound to calciseptine, amlodipine, or a combination of amiodarone and sofosbuvir, exhibit a consistent inactivated conformation with a sealed gate, three up voltage-sensing domains (VSDs), and a down VSDII. Calciseptine sits on the shoulder of the pore domain, away from the permeation path. In contrast, when pinaverium bromide, an antispasmodic drug, is inserted into a cavity reminiscent of the IFM-binding site in Nav channels, a series of structural changes occur, including upward movement of VSDII coupled with dilation of the selectivity filter and its surrounding segments in repeat III. Meanwhile, S4-5III merges with S5III to become a single helix, resulting in a widened but still non-conductive intracellular gate.