title: The Drosophila myosin VI Jaguar is required for basal protein targeting and correct spindle orientation in mitotic neuroblasts.
abstract: Asymmetric cell divisions generate cellular diversity. In Drosophila, embryonic neuroblasts target cell fate determinants basally, rotate their spindles by 90 degrees to align with the apical-basal axis, and divide asymmetrically in a stem cell-like fashion. In this process, apically localized Bazooka recruits Inscuteable and other proteins to form an apical complex, which then specifies spindle orientation and basal localization of the cell fate determinants and their adapter proteins such as Miranda. Here we report that Miranda localization requires the unconventional myosin VI Jaguar (Jar). In jar null mutant embryos, Miranda is delocalized and the spindle is misoriented, but the Inscuteable crescent remains apical. Miranda directly binds to Jar, raising the possibility that Miranda and its associated proteins are translocated basally by this actin-based motor. Our studies demonstrate that a class VI myosin is necessary for basal protein targeting and spindle orientation in neuroblasts.
authors.affiliation: Howard Hughes Medical Institute, Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA.
authors.forename: Claudia
authors.initials: C
authors.lastname: Petritsch
authors.forename: Gaia
authors.initials: G
authors.lastname: Tavosanis
authors.forename: Christoph W
authors.initials: CW
authors.lastname: Turck
authors.forename: Lily Y
authors.initials: LY
authors.lastname: Jan
authors.forename: Yuh Nung
authors.initials: YN
authors.lastname: Jan
mesh_terms: D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002465:Cell Movement; D016764:Cell Polarity; D003598:Cytoskeletal Proteins / Q000378:metabolism; D029721:Drosophila Proteins / Q000502:physiology*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000166:cytology; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D047908:Intracellular Signaling Peptides and Proteins; D018995:Myosin Heavy Chains / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D009479:Neuropeptides; D034622:RNA Interference; D008941:Spindle Apparatus / Q000502:physiology*
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D029721:Drosophila Proteins; D047908:Intracellular Signaling Peptides and Proteins; C107613:Mira protein, Drosophila; D009479:Neuropeptides; C400774:baz protein, Drosophila; C098678:insc protein, Drosophila; C089785:myosin VI; D018995:Myosin Heavy Chains