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BP: Fachverband Biologische Physik
BP 23: Cytoskeleton (joint BP/CPP)
BP 23.8: Talk
Wednesday, April 2, 2014, 11:45–12:00, HÜL 386
Structural and mechanical properties of the kinetochore: a biophysical approach. — •Gheorghe Cojoc1, Emanuele Roscioli2, Lijuan Zhang3, Iva M. Tolić-Nørrelykke1, Daniela Cimini2, and Juraj Gregan3 — 1Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany — 2Dept. Biological Sciences, Virginia Tech, Blacksburg, VA, USA — 3Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
The equal partitioning of replicated sister chromatids during cell division depends on proper attachment of kinetochores (KTs) to the microtubules (MTs) emanating from opposite poles. The KT is a multidomain structure that assembles during mitosis to create the MT-binding sites on the centromere. Although mounting evidence suggests that the mechanical properties of KTs may contribute to faithful chromosome segregation, an in-depth characterization of such properties is still lacking. Here, we used merotelic KTs as a model to characterize the mechanical properties of different KT subdomains. Merotelic KT attachment is an error in which MTs nucleating from both poles attach to the same KT. Merotelic KTs persisting into anaphase become significantly stretched, which makes them an ideal model to study KT mechanical properties. We developed an in vivo assay to investigate KT mechanics by releasing the forces acting on the merotelic KT and performing live cell imaging at high spatial and temporal resolution. In our assay, the forces on the KT are released by severing (using laser microsurgery) one of the two MT bundles attached to the stretched merotelic KT.