A dual-scale model for the caveolin-mediated vesiculation

Abstract

Caveolae-mediated vesiculation refers to the ∼100 nm cave-like plasma membrane invaginations, which function as macromolecular transport vesicles that regulate cellular function. The initiation of vesiculation is closely associated with protein–protein and protein–membrane interactions, yet their roles in the caveolae budding process are not well-understood. We here propose a dual-scale model, which allows us to identify a unique role for the caveolin–dioleoylphosphatidylserine (DOPS) interaction and the high-order oligomer of caveolins. An energy analysis reveals that the protein–lipid affinity and oligomerization can provide enough energy to increase the local curvature within membrane vesicle formation. Membrane evolution simulations also propose that the radius of the mature vesicle is intrinsic and relies on the molecular interactions, regardless of the oligomer number and surface tension. By introducing molecular interactions at the nanoscale into cellular events occurring in the microscale, the present dual-scale model sheds light on how molecular interactions can change the membrane vesiculation.