Abstract
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.
Highlights
Macropinocytosis is an evolutionarily conserved actin-dependent endocytic process (King and Kay, 2019), in which the extracellular fluid is taken up by internalization of micrometer-scale cup-shaped membrane ruffles (Figure 1A)
SUMMARY Macropinocytosis refers to the non-specific uptake of extracellular fluid, which plays ubiquitous roles in cell growth, immune surveillance, and virus entry
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
Summary
Macropinocytosis is an evolutionarily conserved actin-dependent endocytic process (King and Kay, 2019), in which the extracellular fluid is taken up by internalization of micrometer-scale cup-shaped membrane ruffles (Figure 1A). In contrast to phagocytic cups, which extend along the extracellular particles (Herant et al, 2006; Richards and Endres, 2017) (e.g., other cells to be engulfed for phagocytes, and pathogens for immune cells), there is no such support to guide macropinocytic cups externally. These morphological and dynamical features that are distinct from other endocytic processes indicate a mechanism unique to macropinocytosis that remains to be elucidated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
