Dresden 2017 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 25: Posters - Cytoskeletal Filaments

BP 25.9: Poster

Dienstag, 21. März 2017, 14:00–16:00, P2-EG

Forces generated and transmitted by the diffusible, microtubule-crosslinking motor protein kinesin-14 — •Annemarie Lüdecke^{1, 2}, Marcus Braun^{1, 2}, Zdenek Lansky^{1, 2, 3}, Anja-Maria Seidel¹, and Stefan Diez^{1, 2} — ¹B CUBE, TU Dresden, Arnoldstraße 18, 01307 Dresden, Germany — ²MPI-CBG, Pfotenhauerstraße 108, 01307 Dresden, Germany — ³CAS, BIOCEV, Prumyslova 595, Vestec 25250, Czech Republic

Faithful cell division critically depends on the ability of the spindle apparatus to exert and withstand high force while dynamically remodeling its entire architecture during mitosis. In this context, microtubule (MT) contacts, facilitated by MT-crosslinking proteins are of vital importance. Crosslinking motors control spindle shape by (i) sliding newly nucleated MTs towards the spindle poles, thereby focusing MTs at the poles, but also by (2) crosslinking MTs from opposing spindle poles in the midzone of the spindle thereby mechanically stabilizing the spindle apparatus. Recently, force contributions of several types of crosslinkers have been described (e.g. of kinesin-5, ase1), but others remain elusive. Here, we quantified both the force generation of kinesin-14 motor domains as well as the force transmission of kinesin-14 full-length proteins in between MTs. We show that force generation by the motor domains is linearly dependent on motor number and that forces above 10 pN can be reached. Furthermore, we show that force transmission as well as sliding velocity are critically regulated by the diffusivity of the kinesin-14 tail domains on the MTs. Our results have implications in the force balance of the mitotic spindle.