title: Targeting Aurora B to the equatorial cortex by MKlp2 is required for cytokinesis.
abstract: Although Aurora B is important in cleavage furrow ingression and completion during cytokinesis, the mechanism by which kinase activity is targeted to the cleavage furrow and the molecule(s) responsible for this process have remained elusive. Here, we demonstrate that an essential mitotic kinesin MKlp2 requires myosin-II for its localization to the equatorial cortex, and this event is required to recruit Aurora B to the equatorial cortex in mammalian cells. This recruitment event is also required to promote the highly focused accumulation of active RhoA at the equatorial cortex and stable ingression of the cleavage furrow in bipolar cytokinesis. Specifically, in drug-induced monopolar cytokinesis, targeting Aurora B to the cell cortex by MKlp2 is essential for cell polarization and furrow formation. Once the furrow has formed, MKlp2 further recruits Aurora B to the growing furrow. This process together with continuous Aurora B kinase activity at the growing furrow is essential for stable furrow propagation and completion. In contrast, a MKlp2 mutant defective in binding myosin-II does not recruit Aurora B to the cell cortex and does not promote furrow formation during monopolar cytokinesis. This mutant is also defective in maintaining the ingressing furrow during bipolar cytokinesis. Together, these findings reveal that targeting Aurora B to the cell cortex (or the equatorial cortex) by MKlp2 is essential for the maintenance of the ingressing furrow for successful cytokinesis.
authors.affiliation: Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Kitagawa
authors.forename: Suet Yin Sarah
authors.initials: SY
authors.lastname: Fung
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Onishi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Saya
authors.forename: Sang Hyun
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000205:Actomyosin / Q000378:metabolism; D064107:Aurora Kinase B / Q000378:metabolism*; D016764:Cell Polarity; D048749:Cytokinesis; D003593:Cytoplasm / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D016547:Kinesins / Q000378:metabolism*; D024462:Myosin Type II / Q000378:metabolism; D021381:Protein Transport
chemical_list: C410089:KIF20A protein, human; D000205:Actomyosin; C576921:AURKB protein, human; D064107:Aurora Kinase B; D024462:Myosin Type II; D016547:Kinesins