  Mechanosensitive (MS) channels are ion channels which act as cells' safety
valves, opening when the osmotic pressure becomes too high and making cells
avoid damage by releasing ions. They are found on the cellular membrane of a
large number of organisms. They interact with each other by means of
deformations they induce in the membrane. We show that collective dynamics
arising from the inter-channel interactions lead to first and second-order
phase transitions in the fraction of open channels in equilibrium relating to
the formation of channel clusters. We show that this results in a considerable
delay of the response of cells to osmotic shocks, and to an extreme
cell-to-cell stochastic variations in their response times, despite the large
numbers of channels present in each cell. We discuss how our results are
relevant for {\it E. coli}.
