A time course of orchestrated endophilin action in sensing, bending, and stabilizing curved membranes.

Publication Type:

Journal Article

Source:

Molecular biology of the cell, Volume 27, Issue 13, p.2119-32 (2016)

Abstract:

Numerous proteins act in concert to sculpt membrane compartments for cell signaling and metabolism. These proteins may act as curvature sensors, membrane benders, and scaffolding molecules. Here, we show that endophilin, a critical protein for rapid endocytosis, quickly transforms from a curvature sensor to an active bender upon membrane association. We find that local membrane deformation does not occur until endophilin inserts its amphipathic helices into lipid bilayers, supporting an active bending mechanism through wedging. Our time-course studies show that endophilin continues to drive membrane changes on the second-to-minute timescale, indicating that the time duration of endocytosis events constrains the mode of endophilin action. Finally, we reveal a requirement of coordinated activities between wedging and scaffolding for endophilin to produce stable membrane tubules in vitro, and to promote synaptic activity in vivo. Together, these data demonstrate that endophilin is a multi-faceted molecule that precisely integrates activities of sensing, bending, and stabilizing curvature to sculpt membranes with speed.