Regensburg 2007 – scientific programme
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BP: Fachverband Biologische Physik
BP 22: Molecular Machines
BP 22.2: Talk
Thursday, March 29, 2007, 10:00–10:15, H43
Bidirectional cargo transport by two species of molecular motors — •Melanie Muller1, Stefan Klumpp2, and Reinhard Lipowsky1 — 1Max Planck Institute of Colloids and Interfaces, Potsdam-Golm, Germany — 2Center for Theoretical Biological Physics, University of California San Diego, USA
Long-range intracellular transport is based on molecular motors that pull cargos along cytoskeletal filaments. One type of motor always moves in one direction, e.g. conventional kinesin moves to the microtubule plus end, while cytoplasmic dynein moves to the microtubule minus end. However, many cellular cargos are observed to move bidirectionally, involving both plus-end and minus-end directed motors. We present a stochastic 'tug-of-war' model for which motors work independently and are only coupled via the mechanical interaction with their common cargo. Depending on the motor parameters (such as microtubule affinity or stall force), we obtain three distinct types of motility behaviour of the cargo: no significant motility, stochastic switching between fast plus and minus end motion, and stochastic switching between all three types of motion. In the parameter range which leads to switches between fast plus and minus end motility, the motors appear to act in a cooperative way in spite of the underlying tug-of-war.