Blount P, Sukharev S I, Moe P C, Nagle S K, Kung C
Laboratory of Molecular Biology, Bock Labs, University of Wisconsin-Madison 53706, USA.
Biol Cell. 1996;87(1-2):1-8.
Whether it be to sense a touch, arterial pressure, or an osmotic gradient across a cell membrane, essentially all living organisms require the capability of detecting mechanical force. Electrophysiological evidence has suggested that mechanosensitive ion channels play a major role in many systems where mechanical force is detected. But, despite their biological importance, determination of the most basic structural and functional features of mechanosensitive channels has only recently become possible. A gene called mscL, which was isolated from Escherichia coli, was the first gene shown to encode a mechanosensitive channel activity. This channel directly responds to tension in the membrane; no other proteins are required. MscL appears to be a homohexamer of a 136 amino acid polypeptide that is highly alpha helical, contains two transmembrane domains, and has both the amino and carboxyl termini in the cytoplasm. The study of the MscL protein remains, to date, one of the most viable options for understanding the structural and functional characteristics of a mechanosensitive channel.
无论是感知触摸、动脉血压还是细胞膜上的渗透梯度，基本上所有生物都需要具备检测机械力的能力。电生理证据表明，机械敏感离子通道在许多检测机械力的系统中起着主要作用。但是，尽管它们具有生物学重要性，确定机械敏感通道最基本的结构和功能特征直到最近才成为可能。从大肠杆菌中分离出的一个名为mscL的基因，是第一个被证明编码机械敏感通道活性的基因。该通道直接对膜中的张力做出反应；不需要其他蛋白质。MscL似乎是一种由136个氨基酸多肽组成的同型六聚体，该多肽高度α螺旋，包含两个跨膜结构域，并且氨基和羧基末端都在细胞质中。迄今为止，对MscL蛋白的研究仍然是理解机械敏感通道结构和功能特征最可行的选择之一。
