Expression of arabidopsis MCA1 enhanced mechanosensitive channel activity in the Xenopus laevis oocyte plasma membrane
Expression of arabidopsis MCA1 enhanced mechanosensitive channel activity in the Xenopus laevis oocyte plasma membrane
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DOI：
10.4161/psb.20783
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发表时间：
2012-01-01
影响因子：
2.9
通讯作者：
Tatsumi, Hitoshi
中科院分区：
文献类型：
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作者：
Furuichi, Takuya;Iida, Hidetoshi;Tatsumi, Hitoshi
高等植物感知并响应渗透和机械压力，如膨胀、触摸、弯曲和重力。根据电生理学和药理学研究，机械敏感通道（Mechanosensitive channels， MS）是由细胞膜和细胞骨架张力直接激活的通道，参与低压条件下的细胞体积调节和对机械应力的感知。然而，植物质谱通道的分子鉴定进展有限。在这里，我们发现MCA1 （mid1互补活性1；在拟南芥中假定的机械敏感的Ca2+渗透通道）增加了非洲爪蟾卵母细胞质膜中的MS通道活性。利用非洲爪蟾卵母细胞表达系统检测了MCA1的功能和动力学特性，结果表明MCA1依赖的MS阳离子电流可通过低渗透冲击或移液管吸吸产生的膜拉伸激活。单通道分析表明，MCA1编码一个电导为34 pS的可能的MS通道。
Higher plants sense and respond to osmotic and mechanical stresses such as turgor, touch, flexure and gravity. Mechanosensitive (MS) channels, directly activated by tension in the cell membrane and cytoskeleton, are supposed to be involved in the cell volume regulation under hypotonic conditions and the sensing of these mechanical stresses based on electrophysiological and pharmacological studies. However, limited progress has been achieved in the molecular identification of plant MS channels. Here, we show that MCA1 (mid1-complementing activity 1; a putative mechanosensitive Ca2+-permeable channel in Arabidopsis thaliana) increased MS channel activity in the plasma membrane of Xenopus laevis oocytes. The functional and kinetic properties of MCA1 were examined by using a Xenopus laevis oocytes expression system, which showed that MCA1-dependent MS cation currents were activated by hypo-osmotic shock or by membrane stretch produced by pipette suction. Single-channel analyses suggest that MCA1 encodes a possible MS channel with a conductance of 34 pS.