Use the force: membrane tension as an organizer of cell shape and motility

Abstract

Many cell phenomena that involve shape changes are affected by the intrinsic deformability of the plasma membrane (PM). Far from being a passive participant, the PM is now known to physically, as well as biochemically, influence cell processes ranging from vesicle trafficking to actin assembly. Here we review current understanding of how changes in PM tension regulate cell shape and movement, as well as how cells sense PM tension.

Figure 1. Feedback between plasma membrane tension and cellular processes

Examples of cellular processes that occur when PM tension is too high and that lead to its reduction (left) or that occur when PM tension is too low and lead to its increase (right) — vesicle trafficking, caveolae formation, actin polymerization and changes in myosin based. In brackets we comment on the parameters of Eq. 1 and 2 in Box 2 that are predicted to change in each of these processes.

Figure 2. Sensing membrane tension

PM in a resting cell (left) or following an increase in PM tension, as observed during cell protrusion or cell spreading (right). PM tension could be sensed by the opening of stretch activated ion channels (top), the dissociation of curvature-sensitive membrane-binding proteins (middle), or changes in the activity of membrane-to-cortex attachment proteins (bottom).