Identification of a novel beta-catenin-interacting protein.
Cadherin is a well-known cell-cell adhesion molecule, and it binds to beta-catenin, which in turn binds to alpha-catenin. However, little is known about the regulatory mechanism underlying the cadherin-mediated cell-cell adhesion. Here we purified two novel beta-catenin-interacting proteins with molecular masses of 180 kDa (p180) and 150 kDa (p150) from bovine brain cytosol by using glutathione S-transferase (GST)-beta-catenin affinity column chromatography. Mass spectral analysis revealed p180 to be identical to KIAA0313 which has a putative Rap1 guanine nucleotide exchange factor (GEF) domain and p150 to be the same as KIAA0705 which has a high degree of sequence similarity to the synaptic scaffolding molecule (S-SCAM), which binds beta-catenin and KIAA0313 in the yeast two-hybrid system and overlay assay, respectively (Ide et al., Biochem. Biophys. Res. Commun. 256, 456-461, 1999; Ohtsuka et al., Biochem. Biophys. Res. Commun. 265, 38-44, 1999). beta-Catenin was coimmunoprecipitated with KIAA0313 in Madin-Darby canine kidney II (MDCKII) cells, bovine brain cytosol, and EL cells. KIAA0313 and beta-catenin were partly colocalized at sites of cell-cell contact in MDCKII cells. Taken together, our data suggest that KIAA0313 associates with beta-catenin through KIAA0705 in vivo at sites of cell-cell contact.
Kawajiri
A
A
Division of Signal Transduction, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, 630-0101, Japan.
Itoh
N
N
Fukata
M
M
Nakagawa
M
M
Yamaga
M
M
Iwamatsu
A
A
Kaibuchi
K
K
D000818:Animals; D015820:Cadherins / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D002448:Cell Adhesion; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004285:Dogs; D066298:In Vitro Techniques; D051379:Mice; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D015534:Trans-Activators; D051176:beta Catenin
C495267:CTNNB1 protein, mouse; D015820:Cadherins; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D009419:Nerve Tissue Proteins; D015534:Trans-Activators; D051176:beta Catenin