membranecurving

Membranecurving refers to the bending and shaping of biological membranes into curved geometries. This process is fundamental to cellular organization, enabling vesicle formation, tubule extension, and the maintenance of organelle architecture. While membranes can bend spontaneously under certain conditions, membranecurving is typically driven by specialized proteins and mechanical forces that act on the lipid bilayer.

Mechanisms of membranecurving include the action of curvature-generating proteins that scaffold or insert into the membrane, such as BAR-domain proteins and clathrin-associated coats. These proteins can assemble into lattices or impose anisotropic curvature. Lipid composition also influences curvature; conically shaped lipids and asymmetries between leaflets promote bending. Cytoskeletal forces, membrane tension, and osmotic gradients provide additional driving forces, while dynamin-related scission proteins can constrict and sever highly curved regions to release vesicles.

Membranecurving is central to processes such as endocytosis, exocytosis, and intracellular trafficking. It shapes the ER and Golgi membranes into tubules and cisternae, contributes to the formation of caveolae in the plasma membrane, and participates in mitochondrial and peroxisomal morphogenesis. Proper curvature is essential for efficient cargo sorting, membrane fusion, and organelle biogenesis.

Theoretical and experimental approaches describe membranecurving in terms of bending energy and curvature elasticity. The Helfrich model expresses the energy cost of bending a membrane in terms of bending rigidity and spontaneous curvature. Experimental methods include cryo-electron tomography, fluorescence and super-resolution microscopy, and in vitro reconstitution with purified proteins and synthetic liposomes, often combined with molecular dynamics simulations.

Membranecurving remains a multidisciplinary topic, linking biophysics, cell biology, and materials science to understand how cells sculpt their membranes.