title: Interaction of lp-dlg/KIAA0583, a membrane-associated guanylate kinase family protein, with vinexin and beta-catenin at sites of cell-cell contact.
abstract: Vinexin is a recently identified cytoskeletal protein and plays a key role in the regulation of cytoskeletal organization and signal transduction. Vinexin localizes at sites of cell-extracellular matrix adhesion in NIH3T3 fibroblasts and at sites of cell-cell contact in epithelial LLC-PK1 cells. Expression of vinexin promotes the formation of actin stress fiber, but the role of vinexin at sites of cell-cell contact is unclear. Here we identified lp-dlg/KIAA0583 as a novel binding partner for vinexin by using yeast two-hybrid screening. lp-dlg/KIAA0583 has a NH2-terminal coiled-coil-like domain, in addition to four PDZ domains, an Src homology (SH) 3 domain, and a guanylate kinase domain, which are conserved structures in membrane-associated guanylate kinase family proteins. The third SH3 domain of vinexin bound to the region between the second and third PDZ domain of lp-dlg, which contains a proline-rich sequence. lp-dlg colocalized with vinexin at sites of cell-cell contact in LLC-PK1 cells. Furthermore, lp-dlg colocalized with beta-catenin, a major adherens junction protein, in LLC-PK1 cells. Co-immunoprecipitation experiments revealed that both endogenous and epitope-tagged deletion mutants of lp-dlg/KIAA0583 associated with beta-catenin. We also showed that these three proteins could form a ternary complex. Together these findings suggest that lp-dlg/KIAA0583 is a novel scaffolding protein that can link the vinexin-vinculin complex and beta-catenin at sites of cell-cell contact.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Wakabayashi
authors.forename: Takuya
authors.initials: T
authors.lastname: Ito
authors.forename: Masaru
authors.initials: M
authors.lastname: Mitsushima
authors.forename: Sanae
authors.initials: S
authors.lastname: Aizawa
authors.forename: Kazumitsu
authors.initials: K
authors.lastname: Ueda
authors.forename: Teruo
authors.initials: T
authors.lastname: Amachi
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kioka
mesh_terms: D016475:3T3 Cells; D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D019556:COS Cells; D002450:Cell Communication; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D000074288:Discs Large Homolog 1 Protein; D004847:Epithelial Cells / Q000378:metabolism; D017353:Gene Deletion; D016147:Genes, Tumor Suppressor; D005982:Glutathione Transferase / Q000378:metabolism; D051528:Guanylate Kinases; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry / Q000378:metabolism*; D009703:Nucleoside-Phosphate Kinase / Q000737:chemistry* / Q000235:genetics; D016133:Polymerase Chain Reaction; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014018:Tissue Distribution; D015534:Trans-Activators / Q000737:chemistry / Q000378:metabolism*; D025521:Tumor Suppressor Proteins; D020798:Two-Hybrid System Techniques; D051176:beta Catenin; D018909:src Homology Domains
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C495270:CTNNB1 protein, human; C495267:CTNNB1 protein, mouse; D003598:Cytoskeletal Proteins; C513314:DLG1 protein, human; C114461:DLG5 protein, human; D018076:DNA, Complementary; D000074288:Discs Large Homolog 1 Protein; C000614189:Dlg1 protein, mouse; D008565:Membrane Proteins; D009124:Muscle Proteins; D011506:Proteins; D011993:Recombinant Fusion Proteins; C486523:SORBS3 protein, human; C117452:Sorbs3 protein, mouse; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins; D051176:beta Catenin; D005982:Glutathione Transferase; D009703:Nucleoside-Phosphate Kinase; D051528:Guanylate Kinases