Catchbonding, characterized by the increase of the molecular bond lifetime in response to applied forces is observed for biological macromolecules, including motor proteins within cells. Hitherto, the primary biological functional role of catchbonding was thought to be that of improving adhesion properties of cells to surfaces when subject to tensile forces. However, our study reveals that allosteric deformations in dynein motors, which lead to the catchbonding, can also manifest as a generic mechanism to generate spontaneous mechanical oscillations in motor-cytoskeletal filament complexes. The resultant phase diagram of such motor-filament systems, characterized by force-induced allosteric deformations exhibits bistability and sustained limit-cycle oscillations in biologically relevant regimes, such as for catchbonded dynein. The results elucidate the central role of this mechanism in fashioning a distinctive stability behavior and oscillations in motor-filament complexes such as mitotic spindles. In essence, this study uncovers a crucial functional role of the biological catchbonding in intracellular processes ranging from spindle oscillations during cell division to intracellular transport.

Reference:
Biophys. J, 120, 4129 (2021)