The study adds a biomechanical perspective to the knowledge of vesicle transport regulation. Shuttling vesicle-embedded proteins from cytosol to the plasma membrane is an essential process for living cells. Biochemists have discovered a high number of proteins that contribute to this intricate regulation mostly by monitoring their phosphorylation status. Likewise numerous biophysical studies have explored the mechanics of single motor proteins of the myosin, dynein and kinesin families involved.
Here, a biomechanical approach is taken, where in living cells the tension of the cytoskeletal network is monitored by atomic force microscopy. This network spans all cells and thereby constitutes a supramolecular (mesoscopic) stiffness of the cell body.
The idea of the authors was that vesicles, driven by motor proteins along a fiber, face a resistance of crossing fibers, which varies with the tension of this network. The experiments performed on rat kidney cells favor this view. The vesicle transport is accelerated when the network fibers relax. In simple words, a physically relaxed cell is doing much better in vesicle transport compared to a cell under tension. This finding indicates that intracellular vesicle trafficking has a strong biomechanical component.
|Contact: Ellen R. Weiss|