title: Vitronectin induces phosphorylation of ezrin/radixin/moesin actin-binding proteins through binding to its novel neuronal receptor telencephalin.
abstract: Vitronectin (VN) is an extracellular matrix protein abundantly present in blood and a wide variety of tissues and plays important roles in a number of biological phenomena mainly through its binding to αV integrins. However, its definite function in the brain remains largely unknown. Here we report the identification of telencephalin (TLCN/ICAM-5) as a novel VN receptor on neuronal dendrites. VN strongly binds to TLCN, a unique neuronal member of the ICAM family, which is specifically expressed on dendrites of spiny neurons in the mammalian telencephalon. VN-coated microbeads induce the formation of phagocytic cup-like plasma membrane protrusions on dendrites of cultured hippocampal neurons and trigger the activation of TLCN-dependent intracellular signaling cascade including the phosphorylation of ezrin/radixin/moesin actin-binding proteins and recruitment of F-actin and phosphatidylinositol 4,5-bisphosphate for morphological transformation of the dendritic protrusions. These results suggest that the extracellular matrix molecule VN and its neuronal receptor TLCN play a pivotal role in the phosphorylation of ezrin/radixin/moesin proteins and the formation of phagocytic cup-like structures on neuronal dendrites.
authors.affiliation: Laboratory for Neurobiology of Synapse, RIKEN Brain Science Institute, Saitama 351-0198, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Furutani
authors.forename: Miwa
authors.initials: M
authors.lastname: Kawasaki
authors.forename: Hitomi
authors.initials: H
authors.lastname: Matsuno
authors.forename: Sachiko
authors.initials: S
authors.lastname: Mitsui
authors.forename: Kensaku
authors.initials: K
authors.lastname: Mori
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yoshihara
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D003598:Cytoskeletal Proteins / Q000737:chemistry*; D003712:Dendrites / Q000502:physiology; D005786:Gene Expression Regulation; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008840:Microfilament Proteins / Q000737:chemistry*; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D010587:Phagocytosis; D010766:Phosphorylation; D011485:Protein Binding; D019096:Vitronectin / Q000737:chemistry / Q000502:physiology*; D000099149:Ezrin
chemical_list: D003598:Cytoskeletal Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D019096:Vitronectin; D000099149:Ezrin; C504585:Icam5 protein, mouse; C071058:moesin; C071776:radixin