Calmodulin-dependent activation and inactivation of anoctamin calcium-gated chloride channels.
Calmodulin-dependent activation and inactivation of anoctamin calcium-gated chloride channels.
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DOI：
10.1085/jgp.201311015
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发表时间：
2013-10
期刊：
影响因子：
--
通讯作者：
Möhrlen F
中科院分区：
文献类型：
--
作者：
Vocke K;Dauner K;Hahn A;Ulbrich A;Broecker J;Keller S;Frings S;Möhrlen F
钙依赖性氯离子通道在多种生物系统中起着重要作用。在细胞钙信号的驱动下，通道共同决定兴奋过程并促进溶质运输。anooctamin （ANO）膜蛋白家族编码三个钙激活的氯离子通道，分别命名为ano1（也称为TMEM16A）、ano2（也称为TMEM16B）和ano6（也称为TMEM16F）。在这里，我们研究了ANO 1和ANO 2如何在通道激活过程中使用非平稳电流分析与Ca2+/钙调蛋白相互作用。我们在通道蛋白的n端区域发现了一个推测的钙调素结合域，该区域参与通道激活。与多肽的结合研究表明，该结构域是一种调节性钙调素结合基元（RCBM），与Ca2+/钙调素提供了两种不同的相互作用模式，一种在亚微摩尔Ca2+浓度下，一种在微摩尔Ca2+范围内。功能、结构和药理学数据支持钙调素作为钙传感器与RCBM结构域稳定相关并调节ANO 1和ANO 2通道的激活的概念。此外，大脑中主要的ano2剪接变体表现出Ca2+/钙调素依赖性失活，在30秒内失去通道活性。这种特性可能会在神经元持续的Ca2+信号中减少ANO 2的活性。突变数据表明RCBM结构域也参与了ANO 2的失活，并且在视网膜ANO 2剪接变异体中失活受到抑制。这些结果促进了Ca2+在异辛胺Cl -通道中的调控及其对异辛胺通道在神经元和其他细胞类型中的生理功能的意义。
Calcium-dependent chloride channels serve critical functions in diverse biological systems. Driven by cellular calcium signals, the channels codetermine excitatory processes and promote solute transport. The anoctamin (ANO) family of membrane proteins encodes three calcium-activated chloride channels, named ANO 1 (also TMEM16A), ANO 2 (also TMEM16B), and ANO 6 (also TMEM16F). Here we examined how ANO 1 and ANO 2 interact with Ca2+/calmodulin using nonstationary current analysis during channel activation. We identified a putative calmodulin-binding domain in the N-terminal region of the channel proteins that is involved in channel activation. Binding studies with peptides indicated that this domain, a regulatory calmodulin-binding motif (RCBM), provides two distinct modes of interaction with Ca2+/calmodulin, one at submicromolar Ca2+ concentrations and one in the micromolar Ca2+ range. Functional, structural, and pharmacological data support the concept that calmodulin serves as a calcium sensor that is stably associated with the RCBM domain and regulates the activation of ANO 1 and ANO 2 channels. Moreover, the predominant splice variant of ANO 2 in the brain exhibits Ca2+/calmodulin-dependent inactivation, a loss of channel activity within 30 s. This property may curtail ANO 2 activity during persistent Ca2+ signals in neurons. Mutagenesis data indicated that the RCBM domain is also involved in ANO 2 inactivation, and that inactivation is suppressed in the retinal ANO 2 splice variant. These results advance the understanding of Ca2+ regulation in anoctamin Cl− channels and its significance for the physiological function that anoctamin channels subserve in neurons and other cell types.
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DOI：
10.1073/pnas.262372999
发表时间：
2002-12-24
影响因子：
11.1
作者：
Alseikhan, BA;DeMaria, CD;Yue, DT
通讯作者：
Yue, DT
影响因子：
3.4
作者：
Del Carlo, B;Pellegrini, M;Pellegrino, M
通讯作者：
Pellegrino, M
TMEM16A 在小鼠平滑肌中的表达谱和蛋白质翻译
影响因子：
5.5
作者：
Davis, Alison J.;Forrest, Abigail S.;Leblanc, Normand
通讯作者：
Leblanc, Normand
影响因子：
4
作者：
DURHAM, ACH
通讯作者：
DURHAM, ACH
影响因子：
56.9
作者：
Bradley, J;Reuter, D;Frings, S
通讯作者：
Frings, S