TU: Cdk1 negatively regulates midzone localization of the mitotic kinesin Mklp2 and the chromosomal passenger complex

The survival of eukaryotesdepends on the accurate coordi-nation of mitosis with cytokinesis. Key for the coordination of both processes is the chromosomal passenger complex (CPC) comprising Aurora-B, INCENP, survivin, and borealin [1-5]. The translocation of the CPC from centromeres to the spindle midzone, a structure composed of antiparallel microtubules, at anaphase onset is critical for the comple-tion of cytokinesis [6-12]. In mammalian cells, the mitotic kinesin Mklp2 is essential for recruitment of the CPC to the spindle midzone [13]. However, the mechanism regulating the binding of Mklp2 to microtubules has remained unknown. Here, we demonstrate that Mklp2 and the CPC mutually depend on each other for midzone localization; i.e., Mklp2 is mislocalized in INCENP-RNAi cells and vice versa. Remarkably, INCENP is required for localization o