title: Phosphorylation of ZEN-4/MKLP1 by aurora B regulates completion of cytokinesis.
abstract: The central spindle regulates the formation and positioning of the contractile ring and is essential for completion of cytokinesis [1]. Central spindle assembly begins in early anaphase with the bundling of overlapping, antiparallel, nonkinetochore microtubules [2, 3], and these bundles become compacted and mature into the midbody. Prominent components of the central spindle include aurora B kinase and centralspindlin, a complex containing a Kinesin-6 protein (ZEN-4/MKLP1) and a Rho family GAP (CYK-4/MgcRacGAP) that is essential for central spindle assembly [4]. Centralspindlin localization depends on aurora B kinase [5]. Aurora B concentrates in the midbody and persists between daughter cells. Here, we show that in C. elegans embryos and in cultured human cells, respectively, ZEN-4 and MKLP1 are phosphorylated by aurora B in vitro and in vivo on conserved C-terminal serine residues. In C. elegans embryos, a nonphosphorylatable mutant of ZEN-4 localizes properly but does not efficiently support completion of cytokinesis. In mammalian cells, an inhibitor of aurora kinase acutely attenuates phosphorylation of MKLP1. Inhibition of aurora B in late anaphase causes cytokinesis defects without disrupting the central spindle. These data indicate a conserved role for aurora-B-mediated phosphorylation of ZEN-4/MKLP1 in the completion of cytokinesis.
authors.affiliation: Research Institute of Molecular Pathology, Vienna, Austria.
authors.forename: Annika
authors.initials: A
authors.lastname: Guse
authors.forename: Masanori
authors.initials: M
authors.lastname: Mishima
authors.forename: Michael
authors.initials: M
authors.lastname: Glotzer
mesh_terms: D000818:Animals; D064107:Aurora Kinase B; D064127:Aurora Kinases; D015153:Blotting, Western; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D003001:Cloning, Molecular; D048749:Cytokinesis / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D016547:Kinesins / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism*; D014162:Transfection
chemical_list: D029742:Caenorhabditis elegans Proteins; C490517:MKLP1 protein, C elegans; D008869:Microtubule-Associated Proteins; C114455:ZEN-4 protein, C elegans; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D016547:Kinesins