Journal of Biological Chemistry
Volume 285, Issue 37, 10 September 2010, Pages 28667-28673
Journal home page for Journal of Biological Chemistry

Cell Biology
Polo Kinase Interacts with RacGAP50C and Is Required to Localize the Cytokinesis Initiation Complex*

https://doi.org/10.1074/jbc.M110.103887Get rights and content
Under a Creative Commons license
open access

The assembly and constriction of an actomyosin contractile ring in cytokinesis is dependent on the activation of Rho at the equatorial cortex by a complex, here termed the cytokinesis initiation complex, between a microtubule-associated kinesin-like protein (KLP), a member of the RacGAP family, and the RhoGEF Pebble. Recently, the activity of the mammalian Polo kinase ortholog Plk1 has been implicated in the formation of this complex. We show here that Polo kinase interacts directly with the cytokinesis initiation complex by binding RacGAP50C. We find that a new domain of Polo kinase, termed the intermediate domain, interacts directly with RacGAP50C and that Polo kinase is essential for localization of the KLP-RacGAP centralspindlin complex to the cell equator and spindle midzone. In the absence of Polo kinase, RacGAP50C and Pav-KLP fail to localize normally, instead decorating microtubules along their length. Our results indicate that Polo kinase directly binds the conserved cytokinesis initiation complex and is required to trigger centralspindlin localization as a first step in cytokinesis.

Cell Cycle
Cell Division
Drosophila Genetics
Fluorescence Resonance Energy Transfer (FRET)
Mitotic Spindle
Cytokinesis
Polo Kinase
Centralspindlin

Cited by (0)

*

This work was supported by funding from the National Health and Medical Research Council of Australia, the Australian Research Council, the Australian National University, and the University of Adelaide.

The on-line version of this article (available at http://www.jbc.org) contains supplemental Movies SV1–SV5 and Figs. S1–S4.