瞬时受体电位通道蛋白4（TRPM4）是一种钙激活的非选择性阳离子通道，可介导细胞膜去极化。

TRPM4 is a Ca2+-activated nonselective cation channel mediating cell membrane depolarization.

作者信息

Launay Pierre, Fleig Andrea, Perraud Anne Laure, Scharenberg Andrew M, Penner Reinhold, Kinet Jean Pierre

机构信息

Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.

出版信息

Cell. 2002 May 3;109(3):397-407. doi: 10.1016/s0092-8674(02)00719-5.

DOI:10.1016/s0092-8674(02)00719-5

PMID:12015988

Abstract

Calcium-activated nonselective (CAN) cation channels are expressed in various excitable and nonexcitable cells supporting important cellular responses such as neuronal bursting activity, fluid secretion, and cardiac rhythmicity. We have cloned and characterized a second form of TRPM4, TRPM4b, a member of the TRP channel family, as a molecular candidate of a CAN channel. TRPM4b encodes a cation channel of 25 pS unitary conductance that is directly activated by [Ca2+]i with an apparent K(D) of approximately 400 nM. It conducts monovalent cations such as Na+ and K+ without significant permeation of Ca2+. TRPM4b is activated following receptor-mediated Ca2+ mobilization, representing a regulatory mechanism that controls the magnitude of Ca2+ influx by modulating the membrane potential and, with it, the driving force for Ca2+ entry through other Ca2+-permeable pathways.

摘要

钙激活非选择性（CAN）阳离子通道在各种可兴奋和不可兴奋细胞中表达，支持重要的细胞反应，如神经元爆发活动、液体分泌和心脏节律性。我们已经克隆并鉴定了TRPM4的第二种形式TRPM4b，它是TRP通道家族的成员，作为CAN通道的分子候选物。TRPM4b编码一个25 pS单位电导的阳离子通道，该通道由细胞内钙离子浓度（[Ca2+]i）直接激活，其表观解离常数（K(D)）约为400 nM。它传导单价阳离子，如Na+和K+，而Ca2+无明显通透。TRPM4b在受体介导的Ca2+动员后被激活，代表一种调节机制，通过调节膜电位以及通过其他Ca2+可渗透途径进入Ca2+的驱动力来控制Ca2+内流的幅度。