Regensburg 2010 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 7: Posters: Biological Machines, Motor Proteins
BP 7.5: Poster
Montag, 22. März 2010, 17:15–20:00, Poster B1
A fast tetrameric Kinesin-5/Kinesin-1 chimera - a tool to study mechanisms of Kinesin-5 regulation — •Christina Thiede1,2, Stefan Lakämper1,2, Alok D. Weßel1, Stefanie Reiter1, and Christoph F. Schmidt1 — 1Drittes Physikalisches Institut, Georg-August-Universität Göttingen, Germany — 2these authors contributed equally to this work
The homo-tetrameric Kinesin-5 motor protein Eg5 from X. laevis drives relative sliding of anti-parallel microtubules (MT) by the processive action of its two opposing sets of dimeric motors. On a single MT, individual tetrameric motors move slowly (≈ 20 nm/s), but processively, alternating between a diffusional and a directional mode, while motors moving between two MTs move in a highly directional and processive fashion. In order to obtain a tetrameric model system with more easy discernable properties and motile phases, we have constructed a tetrameric chimera by replacing Eg5 motor domain and neck linker by the homologous regions of D. melanogaster Kinesin-1 (DK4mer). In surface-gliding assays, Dk4mer showed fast motility (553 ± 31 nm/s). Single GFP-tagged DK4mer motors moved processively along MT at comparable speeds (499 ± 3 nm/s). We observe clearly distinguished directional and diffusional episodes and an overall run length of ≈ 9 µm. The DK4mer is thus an excellent model system to study regulatory aspects of Kinesin-5 due to its high speed, its long processivity and its clear separation of diffusive and directional motility.