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Aurora B Kinase Activity is Required to Prevent Polar Cortical Ingression during Cytokinesis
Kenji Miyauchi, Xiaodong Zhu, Charlene Foong, Hiroshi Hosoya and Maki Murata-Hori
volume 6 | issue 20
15 October 2007Pages: 2549 - 2553
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Cytokinesis requires proper regulation of microtubule dynamics. It has been suggested that dynamic astral microtubules prevent cortical ingression. However, it remains unknown how astral microtubules maintain their dynamic state. Here we show that aurora B kinase, a component of the chromosome passenger complex, is required to sustain the dynamic state of astral microtubules during cytokinesis. Treatment of HeLa cells with Hesperadin, an inhibitor of aurora B kinase, caused abnormal cortical protrusion, leading to cortical ingression in the protruding region and cytokinesis failure. Actin filaments, myosin II, and RhoA failed to localize at the equator but instead distributed along the lateral and/or polar cortex in cells treated with Hesperadin. Time-lapse analyses of microtubule dynamics showed that, in cells treated with Hesperadin, abnormally bundled astral microtubules targeted the protruding region. Mitotic kinesin-like protein 1 (MKLP1), a component of the spindle midzone required for bundling of microtubules, was not detected along bundled astral microtubules in cells treated with Hesperadin, suggesting that factors other than MKLP1 may be involved in this process. Our results suggest that aurora B kinase activity is required for proper regulation of microtubule dynamics to ensure that cytokinesis occurs precisely at the cell equator.
Authors
Kenji Miyauchi
Hiroshima University; Hiroshima, Japan
Xiaodong Zhu
Temasek Life Sciences Laboratory; Singapore
Charlene Foong
Temasek Life Sciences Laboratory; Singapore
Hiroshi Hosoya
Hiroshima University; Hiroshima, Japan
Maki Murata-Hori
Temasek Life Sciences Laboratory; Singapore