Living cells sense their environment and respond to its changes through proteins integrated into their outer membrane. These proteins mediate a broad range of cellular activities, including active and passive transport of materials across the membrane as well as response to osmotic shock, which can strain the cell membrane to the point of catastrophic bursting. Cells protect themselves through so-called mechanosensitive channels that open before the membrane tension grows too large. Molecular dynamics simulations and advanced analysis using NAMD and VMD have revealed in a recent report how the joint mechanics of membrane and protein opens a mechanosensitive channel called MscL. The finding promises to revolutionize the modern view of membrane - protein interaction: the membrane, far from being a homogeneous elastic sheet, exhibits a dramatic variation of tension across its thickness that proves to be decisive for the opening of MscL. More here.