title: Possible role of cortactin phosphorylation by protein kinase Cα in actin-bundle formation at growth cone.
abstract: BACKGROUND
  Cortactin contributes to growth cone morphogenesis by forming with dynamin, ring-shaped complexes that mechanically bundle and stabilise F-actin. However, the regulatory mechanism of cortactin action is poorly understood.
  
  
  RESULTS
  Immunofluorescence microscopy revealed that protein kinase C (PKC) α colocalises with cortactin at growth cone filopodia in SH-SY5Y neuroblastoma cells. PKC activation by phorbol 12-myristate 13-acetate causes cortactin phosphorylation, filopodial retraction and F-actin-bundle loss. Moreover, PKCα directly phosphorylates cortactin in vitro at S135/T145/S172, mitigating both cortactin's actin-binding and actin-crosslinking activity, whereas cellular expression of a phosphorylation-mimetic cortactin mutant hinders filopodial formation with a significant decrease of actin bundles.
  
  
  CONCLUSIONS
  Our results indicate that PKC-mediated cortactin phosphorylation might be implicated in the maintenance of growth cone.
authors.affiliation: Department of Neuroscience, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kita-ku, Okayama, 700-8558, Japan.|CREST, Japan Science and Technology Agency, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamada
authors.affiliation: Department of Neuroscience, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kikuchi
authors.affiliation: Department of Cell Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Masumoto
authors.affiliation: Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, 860-8556, Japan.
authors.forename: Fan-Yan
authors.initials: FY
authors.lastname: Wei
authors.affiliation: Department of Neuroscience, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kita-ku, Okayama, 700-8558, Japan.|CREST, Japan Science and Technology Agency, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Abe
authors.affiliation: Department of Neuroscience, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kita-ku, Okayama, 700-8558, Japan.|CREST, Japan Science and Technology Agency, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Takeda
authors.affiliation: Department of Cell Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Teiichi
authors.initials: T
authors.lastname: Nishiki
authors.affiliation: Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, 860-8556, Japan.
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Tomizawa
authors.affiliation: Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Cell Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Matsui
authors.affiliation: Department of Neuroscience, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kita-ku, Okayama, 700-8558, Japan.|CREST, Japan Science and Technology Agency, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Kohji
authors.initials: K
authors.lastname: Takei
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D045744:Cell Line, Tumor; D051356:Cortactin / Q000378:metabolism*; D020439:Growth Cones / Q000378:metabolism*; D006801:Humans; D008856:Microscopy, Fluorescence; D010766:Phosphorylation; D051571:Protein Kinase C-alpha / Q000378:metabolism*
chemical_list: D000199:Actins; C495868:CTTN protein, human; D051356:Cortactin; D051571:Protein Kinase C-alpha
keywords: Actin bundle; Cortactin; Growth cone; Protein kinase C