title: A kinase-independent role for Aurora A in the assembly of mitotic spindle microtubules in Caenorhabditis elegans embryos.
abstract: The assembly of a functional mitotic spindle is crucial for achieving successful mitosis. Aurora A kinase is one of the key regulators of mitotic events, including mitotic entry, centrosome maturation and spindle bipolarity. Caenorhabditis elegans Aurora A (AIR-1) is responsible for the assembly of γ-tubulin-independent microtubules in early embryos; however, the mechanism by which AIR-1 contributes to microtubule assembly during mitosis has been unclear. Here we show by live-cell imaging and RNA-mediated interference (RNAi)-based modulation of gene activity that AIR-1 has a crucial role in the assembly of chromatin-stimulated microtubules that is independent of the γ-tubulin complex. Surprisingly, the kinase activity of AIR-1 is dispensable for this process. Although the kinase-inactive form of AIR-1 was detected along the microtubules as well as on centrosomes, the kinase-active form of AIR-1 was restricted to centrosomes. Thus, we propose that AIR-1 has a kinase-dependent role at centrosomes and a kinase-independent role for stabilizing spindle microtubules and that coordination of these two roles is crucial for the assembly of mitotic spindles.
authors.affiliation: Laboratory for Developmental Genomics, RIKEN Center for Developmental Biology, Kobe 650-0047, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Toya
authors.forename: Masahiro
authors.initials: M
authors.lastname: Terasawa
authors.forename: Kayo
authors.initials: K
authors.lastname: Nagata
authors.forename: Yumi
authors.initials: Y
authors.lastname: Iida
authors.forename: Asako
authors.initials: A
authors.lastname: Sugimoto
mesh_terms: D000818:Animals; D064127:Aurora Kinases; D015153:Blotting, Western; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000201:enzymology*; D004625:Embryo, Nonmammalian / Q000201:enzymology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D008941:Spindle Apparatus / Q000201:enzymology
chemical_list: D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases