Membrane fission by protein crowding

Significance The division of membrane-bound compartments into smaller, separate volumes is essential to cells. The process of membrane fission is required for the separation of two membrane compartments. The prevailing view has been that to drive fission, proteins must contain specific structural features such as curved scaffolds and wedge-like membrane insertions. In contrast, this work demonstrates a more general mechanism, in which crowding among membrane-bound proteins drives fission. Like a compressed gas, collisions among crowded proteins generate pressure that can stretch, bend, and ultimately disrupt membrane surfaces, leading to fission. The discovery of this mechanism broadens our perspective on membrane fission by demonstrating how any protein, independent of its structure, can assist in this essential cellular process.