The cytoplasmic cage domain of the mechanosensitive channel MscS is a sensor of macromolecular crowding.

ABSTRACT: Cells actively regulate the macromolecular excluded volume of the cytoplasm to maintain the reciprocal fraction of free aqueous solution that is optimal for intracellular processes. However, the mechanisms whereby cells sense this critical parameter remain unclear. The mechanosensitive channel of small conductance (MscS channel), which is the major regulator of turgor in bacteria, mediates efflux of small osmolytes in response to increased membrane tension. At moderate sustained tensions produced by a decrease in external osmolarity, MscS undergoes slow adaptive inactivation; however, it inactivates abruptly in the presence of cytoplasmic crowding agents. To understand the mechanism underlying this rapid inactivation, we combined extrapolated and equilibrium molecular dynamics simulations

SUBMITTER: Rowe I 

PROVIDER: S-EPMC4003192 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature