title: PCTK1 regulates integrin-dependent spindle orientation via protein kinase A regulatory subunit KAP0 and myosin X.
abstract: Integrin-dependent cell-extracellular matrix (ECM) adhesion is a determinant of spindle orientation. However, the signaling pathways that couple integrins to spindle orientation remain elusive. Here, we show that PCTAIRE-1 kinase (PCTK1), a member of the cyclin-dependent kinases (CDKs) whose function is poorly characterized, plays an essential role in this process. PCTK1 regulates spindle orientation in a kinase-dependent manner. Phosphoproteomic analysis together with an RNA interference screen revealed that PCTK1 regulates spindle orientation through phosphorylation of Ser83 on KAP0, a regulatory subunit of protein kinase A (PKA). This phosphorylation is dispensable for KAP0 dimerization and for PKA binding but is necessary for its interaction with myosin X, a regulator of spindle orientation. KAP0 binds to the FERM domain of myosin X and enhances the association of myosin X-FERM with β1 integrin. This interaction between myosin X-FERM and β1 integrin appeared to be crucial for spindle orientation control. We propose that PCTK1-KAP0-myosin X-β1 integrin is a functional module providing a link between ECM and the actin cytoskeleton in the ECM-dependent control of spindle orientation.
authors.affiliation: Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, Japan Department of Cell Biology, Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Iwano
authors.affiliation: Department of Molecular & Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Satou
authors.affiliation: Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, Japan Department of Cell Biology, Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Matsumura
authors.affiliation: Department of Molecular & Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Sugiyama
authors.affiliation: Department of Molecular & Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan yishiham@pharm.kyoto-u.ac.jp ftoyoshi@virus.kyoto-u.ac.jp.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ishihama
authors.affiliation: Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, Japan Department of Cell Biology, Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto, Japan yishiham@pharm.kyoto-u.ac.jp ftoyoshi@virus.kyoto-u.ac.jp.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Toyoshima
mesh_terms: D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D018844:Cyclin-Dependent Kinases / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism*; D021122:Protein Subunits / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D019012:Integrin beta1; C498718:MYO10 protein, human; D021122:Protein Subunits; D017868:Cyclic AMP-Dependent Protein Kinases; D018844:Cyclin-Dependent Kinases; C089463:PCTAIRE-1 protein kinase; D009218:Myosins