FIGURE 1.

Models of the plasma membrane repair process

A: thermodynamic resealing occurs spontaneously due to tension produced by the disordered arrangement of the membrane phospholipids at the open edge of the break. This process is the most likely route of resealing for membrane breaks of ≤1 μm in diameter. B: exocytosis can contribute by trafficking intracellular vesicles to the wounded area where they can fuse with each other and the injured membrane to form a repair patch. C: wound constriction is mediated by caveolae. During this process, caveolae cluster and fuse around larger wounds, leading to wound constriction and intracellular fusion of caveolar endosomes. D: budding/blebbing of the membrane portion containing the wound site with release of the newly formed vesicles into the extracellular space also involves exocytosis. E: exocytosis of an intracellular patch and fusion to the wound site could result in the extracellular release or “shedding” of the wound site. F: endocytosis of wounds occurs via invagination of caveolar vesicles and subsequent intracellular fusion of caveolae.