Dresden 2017 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 43: Cytoskeletal Filaments

BP 43.1: Hauptvortrag

Mittwoch, 22. März 2017, 15:00–15:30, HÜL 386

Diffusive anchorage of molecular motors allows for adaptive force generation — •Stefan Diez — B CUBE, TU Dresden, Germany

Cytoskeletal motor proteins have been well characterized in vitro as single molecules or as ensembles rigidly attached to non-biological substrates. However, in cells, motors are often only loosely coupled to their cargo. Towards understanding the resulting collective transport properties we reconstituted membrane-anchored kinesin-1 gliding motility assays. We found that motor slippage in the membrane rendered the gliding velocity of the microtubules strongly dependent on the number of motors and their diffusivity in the lipid bilayer. Moreover, we investigated the force generation of kinesin-14 motors diffusively anchored with their tail domains on one microtubule while sliding another microtubule. Again, slippage significantly reduced the transport efficiency leading to a strongly reduced force production as compared to rigidly bound motors. Notably, under these conditions the motor forces were low enough to be fully balanced by the entropic forces arising from the diffusive anchorage of non-motor crosslinkers, hence allowing for the adaptive formation of persistent partial microtubule overlaps. Taken together, our results illustrate the importance of motor-cargo coupling, which provides cells with an additional means of regulating transport efficiency and force generation.