Stretch and Change the Channel

Science  18 Dec 1998:
Vol. 282, Issue 5397, pp. 2149
DOI: 10.1126/science.282.5397.2149f

The energy for regulating the downhill flow of inorganic ions across the cellular membrane is usually obtained chemically (opening an ion channel in response to binding of a neurotransmitter) or electrically (opening in response to a change in the transmembrane potential). Chang et al. (p. 2220) present the crystal structure of an ion channel that is regulated mechanically by lateral stretching of the cellular membrane. In the closed state, the channel consists of 10 helices, contributed as pairs from five identical subunits. A funnel-shaped pore is closed off near the cytoplasmic surface, and the suggested mechanism of energy transduction involves an outward displacement of the inner helix of each pair.

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