“Do Cell Membranes Flow Like Honey or Jiggle Like Jello”
Cell membranes experience frequent stretching and poking: from cytoskeletal elements, from osmotic imbalances, from fusion and budding of vesicles, and from forces from the outside. Are the ensuing changes in membrane tension localized near the site of perturbation, or do these changes propagate rapidly through the membrane to distant parts of the cell, perhaps as a mechanical mechanism of long-range signaling? Recently, we found that in many cell types, the cell membrane behaves like a gel, where local mechanical perturbations remain localized for tens of minutes and mediate subcellular signaling events. The largely suppressed flow of lipids in cell membranes can be evaluated in the context of two-dimensional hydrodynamics and poroelasticity. The localization of mechanical perturbations in the cell membrane is a major factor determining the spatial resolution of mechanosensing, the efficiency of membrane homeostasis, and the dynamics of membrane proteins and the cytoskeleton. Finally, I’ll discuss how cells can actively regulate the degree of membrane tension localization through modulating the density and arrangements of immobile transmembrane proteins.
~ Coffee/tea will be served prior to lecture~