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BP: Fachverband Biologische Physik
BP 43: Cytoskeletal Filaments
BP 43.7: Vortrag
Mittwoch, 22. März 2017, 17:00–17:15, HÜL 386
Microtubule pivoting and minus end directed motors drive the formation of the mitotic spindle — •Ivana Ban1, Marcel Prelogović1, Lora Winters2, Ana Milas3, Iva Tolić2,3, and Nenad Pavin1 — 1Faculty of science , University of Zagreb, Croatia — 2Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany — 3Division of Molecular Biology, Ruder Bošković Institute, Zagreb, Croatia
During mitosis, the genetic material is divided into two equal parts by the spindle. This complex micro-machine is made of chromosomes, microtubules (MTs) and a variety of accessory proteins. In the fission yeast Schizosaccharomyces pombe, the mitotic spindle is a bundle of MTs emanating from two spindle pole bodies, whose formation is mediated by motor proteins. A key question is what are the physical principles underlying the formation of a mitotic spindle. In this work, we combine theory and experiment to describe how angular motion of MTs and forces exerted by motor proteins lead to spindle formation. In our model, MTs explore their environment by performing angular movement around the spindle poles, until two MTs come into close proximity, allowing motor proteins accumulate in the overlap region. In the case of minus end directed motors, this leads to formation of antiparallel bundles. We experimentally observed random angular motion of MTs as well as accumulation of Cut7 motor proteins in the overlap region, followed by antiparallel bundle formation. In conclusion, these results provide an explanation for how the angular Brownian motion and motor proteins drive the formation of a stable mitotic spindle.