Molecular identification of a eukaryotic, stretch-activated nonselective cation channel
Molecular identification of a eukaryotic, stretch-activated nonselective cation channel
复制标题
DOI：
10.1126/science.285.5429.882
复制
发表时间：
1999-08-06
期刊：
影响因子：
56.9
通讯作者：
Iida, H
中科院分区：
文献类型：
--
作者：
Kanzaki, M;Nagasawa, M;Iida, H
钙渗透性、牵张激活的非选择性阳离子（SA Cat）通道介导细胞对机械刺激的反应。然而，编码这种通道的基因尚未在真核生物中鉴定。酵母MID1基因产物（Mid1）是酵母Saccharomyces cerevisiae中钙内流所必需的。Midi在中国仓鼠卵巢细胞中的功能性表达赋予了对机械应力的敏感性，这导致钙电导和细胞溶质游离钙浓度的增加。这些增加依赖于细胞外钙的存在，并减少了钆，SA猫通道的阻滞剂。单通道分析与细胞附着的补丁显示，Midi作为一个钙渗透性，阳离子选择性拉伸激活的通道与电导32皮西门子在150毫摩尔氯化铯的移液管。因此，Midi似乎是真核生物的SA Cat通道。
Calcium-permeable, stretch-activated nonselective cation (SA Cat) channels mediate cellular responses to mechanical stimuli. However, genes encoding such channels have not been identified in eukaryotes. The yeast MID1 gene product (Mid1) is required for calcium influx in the yeast Saccharomyces cerevisiae. Functional expression of Midi in Chinese hamster ovary cells conferred sensitivity to mechanical stress that resulted in increases in both calcium conductance and the concentration of cytosolic free calcium. These increases were dependent on the presence of extracellular calcium and were reduced by gadolinium, a blocker of SA Cat channels. Single-channel analyses with cell-attached patches revealed that Midi acts as a calcium-permeable, cation-selective stretch-activated channel with a conductance of 32 picosiemens at 150 millimolar cesium chloride in the pipette. Thus, Midi appears to be a eukaryotic, SA Cat channel.