摘要：SummaryMacropinocytosis refers to the non-specific uptake of extracellular fluid, which plays ubiquitous roles in cell growth, immune surveillance, and virus entry. Despite its widespread occurrence, it remains unclear how its initial cup-shaped plasma membrane extensions form without any external solid support, as opposed to the process of particle uptake during phagocytosis. Here, by developing a computational framework that describes the coupling between the bistable reaction-diffusion processes of active signaling patches and membrane deformation, we demonstrated that the protrusive force localized to the edge of the patches can give rise to a self-enclosing cup structure, without further assumptions of local bending or contraction. Efficient uptake requires a balance among the patch size, magnitude of protrusive force, and cortical tension. Furthermore, our model exhibits cyclic cup formation, coexistence of multiple cups, and cup-splitting, indicating that these complex morphologies self-organize via a common mutually-dependent process of reaction-diffusion and membrane deformation.Graphical abstractDisplay OmittedHighlights•A mathematical model of macropinocytosis cup formation and closure is proposed•A self-enclosing cup emerges from reaction-diffusion pattern on a deformable membrane•Cup-like membrane deformation can arise without curvature-inducing molecules•Cup morphology variations explain the conditions and efficiency of fluid uptakeMembrane architecture; Cell biology; Computer modeling
