title: RICS, a novel GTPase-activating protein for Cdc42 and Rac1, is involved in the beta-catenin-N-cadherin and N-methyl-D-aspartate receptor signaling.
abstract: Cadherin adhesion molecules are believed to be important for synaptic plasticity. beta-Catenin, which links cadherins and the actin cytoskeleton, is a modulator of cadherin adhesion and regulates synaptic structure and function. Here we show that beta-catenin interacts with a novel GTPase-activating protein, named RICS, that acts on Cdc42 and Rac1. The RICS-beta-catenin complex was found to be associated with N-cadherin, N-methyl-d-aspartate receptors, and postsynaptic density-95, and localized to the postsynaptic density. Furthermore, the GTPase-activating protein activity of RICS was inhibited by phosphorylation by Ca(2+)/calmodulin-dependent protein kinase II. These results suggest that RICS is involved in the synaptic adhesion- and N-methyl-d-aspartate-mediated organization of cytoskeletal networks and signal transduction. Thus, RICS may regulate dendritic spine morphology and strength by modulating Rho GTPases.
authors.affiliation: Laboratory of Molecular and Genetic Information, Institute for Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Okabe
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakamura
authors.forename: Yukiko Nasu
authors.initials: YN
authors.lastname: Nishimura
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Kohu
authors.forename: Susumu
authors.initials: S
authors.lastname: Ohwada
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Morishita
authors.forename: Tetsu
authors.initials: T
authors.lastname: Akiyama
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004789:Enzyme Activation; D020558:GTP Phosphohydrolases / Q000737:chemistry*; D020690:GTPase-Activating Proteins; D006624:Hippocampus / Q000166:cytology; D006801:Humans; D015151:Immunoblotting; D051379:Mice; D008969:Molecular Sequence Data; D016202:N-Methylaspartate / Q000494:pharmacology*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013347:Subcellular Fractions / Q000378:metabolism; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D051176:beta Catenin; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*
chemical_list: C470196:ARHGAP32 protein, human; C495270:CTNNB1 protein, human; C495267:CTNNB1 protein, mouse; D015820:Cadherins; C495268:Ctnnb1 protein, rat; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary; D020690:GTPase-Activating Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; D051176:beta Catenin; C033652:postsynaptic density proteins; D016202:N-Methylaspartate; D010744:Phosphoric Monoester Hydrolases; D020558:GTP Phosphohydrolases; D020764:cdc42 GTP-Binding Protein; D020830:rac1 GTP-Binding Protein; D020741:rho GTP-Binding Proteins; D002118:Calcium