Mechanosensitive Channels: What Can We Learn from 'simple' Model Systems?

Mechanosensitive ion channels, which convert external mechanical forces into electrical and chemical signals in cells, are diverse. Presently, there is no known common sequence 'signature' that identifies mechanosensitivity. Bacterial mechanosensitive channels gated by membrane tension represent convenient models allowing us to combine structural information with the insights gained from biophysical analysis, biochemistry, genetic screens, bacterial physiology and molecular computation. Here, the conformational transition driven by membrane tension in the bacterial channel MscL is discussed. The predicted pathway suggests roles for distinct protein domains, surrounding lipids and water in the gating process. MscL, a simple system, thus helps us obtain a coherent picture of molecular events, and build concepts and strategies that can be applied to more elaborate mechanosensory systems in the near future.