Identification and characterization of the zebrafish ClC-2 chloride channel orthologs
Identification and characterization of the zebrafish ClC-2 chloride channel orthologs
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DOI：
10.1007/s00424-014-1614-z
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发表时间：
2015-08
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影响因子：
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通讯作者：
Carla Pérez-Rius;Héctor Gaitán-Peñas;R. Estévez;Alejandro Barrallo-Gimeno
中科院分区：
文献类型：
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作者：
Carla Pérez-Rius;Héctor Gaitán-Peñas;R. Estévez;Alejandro Barrallo-Gimeno
ClC-2是一种ClC−通道，属于ClC家族的氯离子通道/转运蛋白。Clc-2的分子作用尚不清楚，Clcn2基因敲除小鼠因不明原因出现失明、不孕和脑白质营养不良。ClC-2在大脑中与黏附分子GlialCAM相关，GlialCAM在一种脑白质营养不良中存在缺陷，参与了髓鞘的动态平衡。为了更深入地了解Clc-2的功能，我们在这项工作中鉴定了斑马鱼中的三个Clc-2同源基因。clcn2a和clcn2b来自硬骨特异的全基因组复制，而clcn2carose来自clcn2b的基因复制。斑马鱼clcn2paralog成体组织和胚胎中的表达模式支持其在复制后的亚功能化，clcn2a在可兴奋组织和clcn2in离子细胞中富含。这三种斑马鱼Clc-2蛋白都能与人类GlialCAM相互作用，从而能够将它们定位于细胞连接，就像它对哺乳动物ClC-2所做的那样。在Xenopus卵母细胞中可以检测到ClC-2a和ClC-2b具有不同的电压依赖性和动力学特征的内向整流氯电流，而ClC-2c仍然处于失活状态。有趣的是，GlialCAM蛋白没有改变CLC-2b的内向整流。然后，我们的工作扩展了ClC-2蛋白的谱系，并为结构功能和生理学研究提供了新的工具。
ClC-2 is a Cl−channel that belongs to the CLC family of chloride channel/transport proteins. ClC-2 molecular role is not clear, andClcn2knockout mice develop blindness, sterility, and leukodystrophy by unknown reasons. ClC-2 is associated in the brain with the adhesion molecule GlialCAM, which is defective in a type of leukodystrophy, involving ClC-2 in the homeostasis of myelin. To get more insight into the functions of ClC-2, we have identified in this work the three ClC-2 orthologs in zebrafish.clcn2aandclcn2bresulted from the teleost-specific whole genome duplication, whileclcn2carose from a gene duplication fromclcn2b. The expression patterns in adult tissues and embryos of zebrafishclcn2paralogs support their subfunctionalization after the duplications, withclcn2abeing enriched in excitable tissues andclcn2cin ionocytes. All three zebrafish clc-2 proteins interact with human GLIALCAM, that is able to target them to cell junctions, as it does with mammalian ClC-2. We could detect clc-2a and clc-2b inward rectified chloride currents with different voltage-dependence and kinetics inXenopusoocytes, while clc-2c remained inactive. Interestingly, GlialCAM proteins did not modify clc-2b inward rectification. Then, our work extends the repertoire of ClC-2 proteins and provides new tools for structure-function and physiology studies.