Bacteria are Stressed Out Too: The Physics of Mechanosensation

Abstract

Many of the ways that cells talk and listen to the external world center on the presence of proteins on the cell surface. Indeed, the cell membrane is an amazingly diverse lipid environment, riddled in turn with a host of different proteins that perform tasks ranging from sensing and measuring chemical signals to the transport of sugars needed for cell division to the detection of potentially lethal osmotic pressures. This talk will focus on recent progress in the dissection of the mechanisms of mechanosensation in bacteria with special reference to the rich interplay between certain classes of ion channels and the surrounding lipids. Using simple arguments from elasticity theory, I will describe the membrane deformation footprint surrounding ion channels and how this deformation footprint contributes to the free energy of channel gating. In turn, I will show how these ideas can be parlayed into an experimental strategy for better understanding mechanosensation by watching individual cells as they are subjected to controlled levels of osmotic shock.