Reciprocal link between cell biomechanics and exocytosis

Abstract

A cell is able to sense the biomechanical properties of the environment such as the rigidity of the extracellular matrix and adapt its tension via regulation of plasma membrane and underlying actomyosin meshwork properties. The cell's ability to adapt to the changing biomechanical environment is important for cellular homeostasis and also cell dynamics such as cell growth and motility. Membrane trafficking has emerged as an important mechanism to regulate cell biomechanics. In this review, we summarize the current understanding of the role of cell mechanics in exocytosis, and reciprocally, the role of exocytosis in regulating cell mechanics. We also discuss how cell mechanics and membrane trafficking, particularly exocytosis, can work together to regulate cell polarity and motility.

Uncovering the “secret” lives of vacuolar fusion pores in living cells

“…This also includes attractive forces within the pore interior or adhesive forces in the contact area of opposing membranes. Advanced imaging techniques, such as cryoelectron microscopy (cryo‐EM) and focused ion‐beam milling combined with scanning electron microscopy (FIB‐SEM), will be methods of choice to provide further structural information about the actual pore diameter and the local organization of the fusion machinery. The requirement for increased membrane tension to open the fusion pore is in line with several theoretical calculations and recent experimental evidence analyzing exocytosis events at the plasma membrane (Kozlov & Chernomordik, ; Wang & Galli, ). Thus, membrane tension becomes a prominent biophysical and physiological regulator.…”

“…The requirement for increased membrane tension to open the fusion pore is in line with several theoretical calculations and recent experimental evidence analyzing exocytosis events at the plasma membrane (Kozlov & Chernomordik, 2015;Wang & Galli, 2018). Thus, membrane tension becomes a prominent biophysical and physiological regulator.…”

Lysosome Fusion Maintains Phagosome Integrity during Fungal Infection

“…These responses are enacted by the plasma membrane, which senses distortion and responds accordingly, activating compensatory fluxes of solutes and osmotically obliged water (Diz-Muñ oz et al, 2013;Hoffmann and Dunham, 1995;Lang et al, 1998). Increased membrane traffic has also been implicated in cell-volume regulation (Gauthier et al, 2009;Wang and Galli, 2018). By contrast, little is known about the ability of organelles and endomembranes to regulate their size.…”

The plasma membrane as a mechanochemical transducer

“…Second, exocytosis contributes to PM area expansion [35,42–45] by adding lipids to the bilayer. Exocytosis occurs in response to PM tension increase [38] (figure 1 a (v)). Interestingly, simple membrane mechanics could drive this process, as stretching a supported lipid bilayer leads to passive absorption of liposomes sitting on top of it [46].…”

“…Similarly, endocytosis arrest has been associated with increased PM tension, as observed for instance during osmotic swelling of rat basophilic leukaemia (RBL) cells [47]. Here again, tension may facilitate molecularly driven exocytosis [38,39].…”