Role of Rho- and Ca^<2+>-dependent signaling mechanisms in the regulation of neuronal actin cytoskeleton

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 17300116
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Neurochemistry/Neuropharmacology
• Research Institution: The University of Tokyo
• Principal Investigator: BITO Haruhiko The University of Tokyo, Graduate School of Medicine, Associate Professor, 大学院・医学系研究科, 助教授 (00291964)
• Project Period (FY): 2005 – 2006
• Keywords: brain and central nervous system / enzyme / gene / signal transduction / molecular biology

Research Abstract

We here investigated the molecular signaling mechanisms underlying Rho- and Ca^<2+>-dependent modifications of neuronal actin cytoskeleton, as well as their physiological downstream consequences.
In order to identify a CaMK subtype involved, in dendrite formation and outgrowth, a systematic RNAi screening was carried out in a cortical neuronal culture system. No effect was seen on dendrites when CaMKIα, CaMKII, or CaMKIV were knocked down by shRNA. In contrast, shRNA of CLICK-III/CaMKIγ produced a robust decrease in dendritic growth, and this was accompanied with a drop in Rac activity. Further experiments suggested an essential role for a CLICK-III/CaMKIγ-STEF-Rac pathway during cortical dendritogenesis (Takemoto-Kimura et al., under revision)..
We next examined the potential impact of two CaMK-like kinases, CLICK-I/DCaMKL1 and CLICK-II/DCaMKL2, on dendritic morphology. Overexpression of splice variants containing an intact doublecortin domain revealed a strong bundling of microtubules, but little effect on actin cytoskeleton (Ohmae et al. J.Biol.Chem. 2006).
During the course of these studies, gene delivery protocols involving lipofection, adenoviral infection or gene gun were optimized. This led to striking discovery of spine morphological aberrance in PSD-95-mutant-expressing neurons (Nonaka et al., J.Neurosci. 2006). We also found that actin cytoskeleton and calcium dynamics may regulate cortactin or Shank localization in either hippocampal or Purkinje cell dendrites (Iki et al. Eur.J.Neurosci., 2005; Fuse et al. in preparation).
Finally, in collaboration with the Narumiya laboratory, we determined that Rho-mDia1-dependent regulation of actin cytoskeleton plays a critical role in the localization of Apc and Src complexes at distinct polarized positions in a migrating cell.

Research Products

• [Journal Article] Molecular identification and characterization of a family of kinases with homology to Ca^<2+>/calmodulin-dependent protein kinases I/IV. (2006)
  • Author(s): Ohmae S et al.
  • Journal Title: J. Biol. Chem. 281 Pages: 20427-20439
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Rho-mDial pathway regulates cell polarity and focal adhesion turnover in migrating cells through mobilizing APC and c-Src. (2006)
  • Author(s): Yamana N. et al.
  • Journal Title: Mol. Cell. Biol. 26 Pages: 6844-6858
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Essential contribution of the ligand-binding βB-βC loop of PDZ1 and PDZ2 in the regulation of postsynaptic clustering, scaffolding and localization of PSD-95. (2006)
  • Author(s): Nonaka et al.
  • Journal Title: J. Neurosci. 26 Pages: 763-774
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Molecular identification and characterization of a family of kinases with homology to Ca2^<+>/calmodulin-dependent protein kinases I/IV (2006)
  • Author(s): Ohmae S, Takemoto-Kimura S, Okamura M, Adachi-Morishima A, Nonaka M, Fuse T, Kida S, Tanji M, Furuyashiki T, Arakawa Y, Narumiya S, Okuno H, Bito H
  • Journal Title: J.Biol.Chem. 281 Pages: 20427-20439
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Rho-mDia1 pathway regulates cell polarity and focal adhesion turnover in migrating cells through mobilizing APC and c-Src (2006)
  • Author(s): Yamana N, Arakawa Y, Nishino T, Kurokawa K, Tanji M, Itoh RE, Monypenny J, Ishizaki T, Bito H, Nozaki K, Hashimoto K, Matsuda M, Narumiya S
  • Journal Title: Mol.Cell Biol. 26 Pages: 6844-6858
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Essential contribution of the ligand-binding βB-βC loop of PDZ1 and PDZ2 in the regulation of postsynaptic clustering, scaffolding and localization of PSD-95 (2006)
  • Author(s): Nonaka M, Doi T, Fujiyoshi Y, Takemoto-Kimura S, Bito H
  • Journal Title: J.Neurosci. 26 Pages: 763-774
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Regulation of neuronal function by CaMK cascades. (in Japanese) (2006)
  • Author(s): Bito H
  • Journal Title: Brain Science Review 2007 (Masao Ito, Nobufumi Kawai eds)(Kuba Productions) Pages: 91-104(238)
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Bidirectional regulation of postsynaptic cortactin distribution by BDNF and NMDA receptor activity. (2005)
  • Author(s): Iki J.et al.
  • Journal Title: Eur. J. Neurosci. 22 Pages: 2985-2994
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] 「研究成果報告書概要(和文)」より (2005)
  • Author(s): Matsuoka Y. et al.
  • Journal Title: Proc. Natl. Acad. Sci. U.S.A. 102 Pages: 16066-16071
• [Journal Article] Bidirectional regulation of postsynaptic cortactin distribution by BDNF and NMDA receptor activity (2005)
  • Author(s): Iki J, Inoue A, Bito H, Okabe S
  • Journal Title: Eur.J.Neurosci. 22 Pages: 2985-2994
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Prostaglandin E receptor EP1 controls impulsive behavior under stress (2005)
  • Author(s): Matsuoka Y, Furuyashiki T, Yamada K, Nagai T, Bito H, Tanaka Y, Kitaoka S, Ushikubi F, Nabeshima T., Narumiya S
  • Journal Title: Proc.Natl.Acad.Sci.USA 102 Pages: 16066-16071
  • Description: 「研究成果報告書概要(欧文)」より
• [Book] ブレインサイエンス・レビュー2007 (伊藤正男・川合述史編) (2006)
  • Author(s): 尾藤晴彦
  • Total Pages: 91-104(238)
  • Publisher: クバプロ社
  • Description: 「研究成果報告書概要(和文)」より