Membrane Mechanics of Endocytosis in Cells with Turgor

Abstract

Endocytosis is an essential process by which cells internalize a piece of plasma membrane and material from the outside. In cells with turgor, pressure opposes membrane defor- mations, and increases the amount of force that has to be generated by the endocytic machinery. To determine this force, and calculate the shape of the membrane, we used physical theory to model an elastic surface under pressure. Accurate fits of experimental profiles are obtained assuming that the coated membrane is highly rigid and preferentially curved at the endocytic site. The forces required from the actin machinery peaks at the onset of deformation, indicating that once invagination has been initiated, endocytosis is unlikely to stall before completion. Coat proteins do not lower the initiation force but may affect the process by the curvature they induce. In the presence of isotropic curvature inducers, pulling the tip of the invagination can trigger the formation of a neck at the base of the invagination. Hence direct neck constriction by actin may not be required, while its pulling role is essential. Finally, the theory shows that anisotropic curvature effectors stabilize membrane invaginations, and the loss of crescent-shaped BAR domain proteins such as Rvs167 could therefore trigger membrane scission.

References in corpus (3)

• Endocytic proteins drive vesicle growth via instability in high membrane tension environment
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• On the modeling of endocytosis in yeast

Cited by in corpus (4)

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• Finite Membrane Thickness Influences Hydrodynamics on the Nanoscale
• Membrane tension is a key determinant of bud morphology in clathrin-mediated endocytosis
• Induced stresses in quasi-spherical elastic vesicles: local and global Laplace-Young law