Berlin 2024 – scientific programme
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BP: Fachverband Biologische Physik
BP 36: Cell Mechanics II
BP 36.3: Talk
Friday, March 22, 2024, 10:30–10:45, H 0112
Coordinated poleward flux of sister kinetochore fibers drives chromosome congression — •Domagoj Božan1, Jelena Martinčić2, Patrik Risteski2, Nenad Pavin1, and Iva Tolić2 — 1Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, 10000 Zagreb, Croatia — 2Division of Molecular Biology, Rudjer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
Chromosome congression and alignment at the spindle equator promote proper chromosome segregation and depend on pulling forces exerted at kinetochore fiber tips together with polar ejection forces. However, kinetochore fibers are also subjected to forces exerted by motor proteins that drive their poleward flux. Here we introduce a flux-driven centering model that relies on flux generated by forces within the overlaps of bridging and kinetochore fibers. This centering mechanism works so that fewer longer kinetochore fibers fluxes faster than the greater number of shorter ones, moving the kinetochores towards the center. We compare this model with the results of speckle microscopy performed by our collaborators and obtain good correspondence with the experiment. Thus, length-dependent sliding forces exerted by the bridging fiber onto kinetochore fibers promote chromosome congression and alignment.
Keywords: Chromosome congression; Prometaphase; Poleward flux; Microtubules; Motor proteins