title: Prickle/spiny-legs isoforms control the polarity of the apical microtubule network in planar cell polarity.
abstract: Microtubules (MTs) are substrates upon which plus- and minus-end directed motors control the directional movement of cargos that are essential for generating cell polarity. Although centrosomal MTs are organized with plus-ends away from the MT organizing center, the regulation of non-centrosomal MT polarity is poorly understood. Increasing evidence supports the model that directional information for planar polarization is derived from the alignment of a parallel apical network of MTs and the directional MT-dependent trafficking of downstream signaling components. The Fat/Dachsous/Four-jointed (Ft/Ds/Fj) signaling system contributes to orienting those MTs. In addition to previously defined functions in promoting asymmetric subcellular localization of 'core' planar cell polarity (PCP) proteins, we find that alternative Prickle (Pk-Sple) protein isoforms control the polarity of this MT network. This function allows the isoforms of Pk-Sple to differentially determine the direction in which asymmetry is established and therefore, ultimately, the direction of tissue polarity. Oppositely oriented signals that are encoded by oppositely oriented Fj and Ds gradients produce the same polarity outcome in different tissues or compartments, and the tissue-specific activity of alternative Pk-Sple protein isoforms has been observed to rectify the interpretation of opposite upstream directional signals. The control of MT polarity, and thus the directionality of apical vesicle traffic, by Pk-Sple provides a mechanism for this rectification.
authors.affiliation: Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, L235, Stanford, CA 94305, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Olofsson
authors.affiliation: Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, L235, Stanford, CA 94305, USA Department of Genetics, Stanford University School of Medicine, 300 Pasteur Drive, L235, Stanford, CA 94305, USA.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Sharp
authors.affiliation: Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, L235, Stanford, CA 94305, USA.
authors.forename: Maja
authors.initials: M
authors.lastname: Matis
authors.affiliation: Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, L235, Stanford, CA 94305, USA.
authors.forename: Bomsoo
authors.initials: B
authors.lastname: Cho
authors.affiliation: Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, L235, Stanford, CA 94305, USA jaxelrod@stanford.edu.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Axelrod
mesh_terms: D000818:Animals; D016764:Cell Polarity; D022162:Cytoplasmic Vesicles / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism*; D006197:Hair / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D060588:LIM Domain Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D020033:Protein Isoforms / Q000378:metabolism; D014921:Wings, Animal / Q000166:cytology / Q000254:growth & development / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D060588:LIM Domain Proteins; D020033:Protein Isoforms; C121600:pk protein, Drosophila
keywords: Drosophila; Microtubules; Planar cell polarity; Prickle; Spiny-legs; Vesicle transport