TY - JOUR T1 - Kinesin-6 Klp9 orchestrates spindle elongation by regulating microtubule sliding and growth JF - bioRxiv DO - 10.1101/2021.02.17.431708 SP - 2021.02.17.431708 AU - Lara K. Krüger AU - Matthieu Gélin AU - Liang Ji AU - Carlos Kikuti AU - Anne Houdusse AU - Manuel Théry AU - Laurent Blanchoin AU - Phong T. Tran Y1 - 2021/01/01 UR - http://biorxiv.org/content/early/2021/02/18/2021.02.17.431708.abstract N2 - Mitotic spindle function depends on the precise regulation of microtubule dynamics and microtubule sliding. Throughout mitosis, both processes have to be orchestrated to establish and maintain spindle stability. We show that during anaphase B spindle elongation in S. pombe, the sliding motor Klp9 (kinesin-6) also promotes microtubule growth in vivo. In vitro, Klp9 can enhance and dampen microtubule growth, depending on the tubulin concentration. This indicates that the motor is able to promote and block tubulin subunit incorporation into the microtubule lattice in order to set a well-defined microtubule growth velocity. Moreover, Klp9 recruitment to spindle microtubules is dependent on its dephosphorylation mediated by XMAP215/Dis1, a microtubule polymerase, to link the regulation of spindle length and spindle elongation velocity. Collectively, we unravel the mechanism of anaphase B, from Klp9 recruitment to the motors dual-function in regulating microtubule sliding and microtubule growth, allowing an inherent coordination of both processes. ER -