title: Cell biological characterization of a multidomain adaptor protein, ArgBP2, in epithelial NMuMG cells, and identification of a novel short isoform.
abstract: ArgBP2 is a member of the SoHo (sorbin-homology) family of adaptor proteins believed to play roles in cell adhesion, cytoskeletal organization, and signaling. We show here a novel splicing isoform of ArgBP2, i.e., ArgBP2™, composed of only three SH3 (src-homology 3) domains and structurally similar to vinexinß. We then characterized the biochemical and cell biological properties of ArgBP2 to compare these with vinexin. Similar to vinexin, ArgBP2 was enriched at focal adhesions in REF52 fibroblast cells and induced anchorage-dependent extracellular signal-regulated kinase activation in NIH3T3 fibroblast cells. In epithelial NMuMG cells, immunofluorescence analyses revealed localization of ArgBP2 at tight junctions (TJs), whereas vinexin was distributed in cytoplasm as well as cell-cell boundaries. During TJ formation, recruitment of ZO-1 to TJs was followed by ArgBP2. Based on mutation analyses, a second SH3 domain was found to be important for ArgBP2 localization to the cell-cell contact sites. These data suggest some role of ArgBP2 in NMuMG cells at TJs that may be distinct from the function of vinexin.
authors.affiliation: Department of Dermatology, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Murase
authors.forename: Hidenori
authors.initials: H
authors.lastname: Ito
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kanoh
authors.forename: Kaori
authors.initials: K
authors.lastname: Sudo
authors.forename: Ikuko
authors.initials: I
authors.lastname: Iwamoto
authors.forename: Rika
authors.initials: R
authors.lastname: Morishita
authors.forename: Philippe
authors.initials: P
authors.lastname: Soubeyran
authors.forename: Mariko
authors.initials: M
authors.lastname: Seishima
authors.forename: Koh-Ichi
authors.initials: K
authors.lastname: Nagata
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D019556:COS Cells; D018938:Caco-2 Cells; D002448:Cell Adhesion; D002460:Cell Line; D016764:Cell Polarity; D003593:Cytoplasm / Q000378:metabolism; D004252:DNA Mutational Analysis; D004847:Epithelial Cells / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D041681:NIH 3T3 Cells; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins; D051381:Rats; D015398:Signal Transduction; D019108:Tight Junctions / Q000378:metabolism*; D018909:src Homology Domains / Q000235:genetics* / Q000502:physiology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D018398:Homeodomain Proteins; D009124:Muscle Proteins; D020033:Protein Isoforms; D016601:RNA-Binding Proteins; C490755:SORBS2 protein, human; C486523:SORBS3 protein, human