RESEARCH ARTICLE Kinesin-4 KIF21B limits microtubule growth to allow rapid centrosome polarization in T cells Peter Jan Hooikaas1†, Hugo GJ Damstra1†, Oane J Gros1, Wilhelmina E van Riel1‡, Maud Martin1§, Yesper TH Smits2, Jorg van Loosdregt2, Lukas C Kapitein1, Florian Berger1*, Anna Akhmanova1* 1Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands; 2Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands Abstract When a T cell and an antigen-presenting cell form an immunological synapse, rapid dynein-driven translocation of the centrosome toward the contact site leads to reorganization of microtubules and associated organelles. Currently, little is known about how the regulation of *For correspondence: microtubule dynamics contributes to this process. Here, we show that the knockout of KIF21B, a
[email protected] (FB); kinesin-4 linked to autoimmune disorders, causes microtubule overgrowth and perturbs
[email protected] (AA) centrosome translocation. KIF21B restricts microtubule length by inducing microtubule pausing typically followed by catastrophe. Catastrophe induction with vinblastine prevented microtubule †These authors contributed overgrowth and was sufficient to rescue centrosome polarization in KIF21B-knockout cells. equally to this work Biophysical simulations showed that a relatively small number of KIF21B molecules can restrict ‡ Present address: Netherlands mirotubule length and promote an imbalance