title: Assembly of the cadherin-catenin complex in vitro with recombinant proteins.
abstract: The cytoplasmic domain of classical cadherins is tightly associated with three proteins termed alpha-, beta- and gamma-catenin. These accessory proteins are of central importance for the adhesive properties of this class of cell adhesion molecules. In order to examine the molecular architecture of the cadherin-catenin complex in more detail we have expressed the catenins and the cytoplasmic domain of E-cadherin as fusion proteins in Escherichia coli, and analyzed the interaction of purified recombinant cadherin and catenins in combinatorial protein-protein interaction experiments. The cytoplasmic domain of E-cadherin cannot directly associate with alpha-catenin but interacts with high affinity with beta-catenin, whereas the binding of gamma-catenin (plakoglobin) to E-cadherin is less efficient. alpha- and beta-catenin assemble into a 1:1 heterodimeric complex. The analysis of various truncated beta-catenins revealed that an alpha-catenin binding site in beta-catenin is localized between amino acid positions 120 and 151. The central role of beta-catenin for the assembly of the heterotrimeric E-cadherin/alpha-catenin/beta-catenin complex in mixing experiments with all components was demonstrated. The reconstitution in vitro of the cadherin-catenin complex should allow the study of the interaction with signalling molecules and with the actin-based cytoskeleton.
authors.affiliation: Max-Planck-Institut für Immunbiologie, Freiburg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Aberle
authors.forename: S
authors.initials: S
authors.lastname: Butz
authors.forename: J
authors.initials: J
authors.lastname: Stappert
authors.forename: H
authors.initials: H
authors.lastname: Weissig
authors.forename: R
authors.initials: R
authors.lastname: Kemler
authors.forename: H
authors.initials: H
authors.lastname: Hoschuetzky
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D051180:Desmoplakins; D004926:Escherichia coli / Q000235:genetics; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin; D051185:gamma Catenin
chemical_list: D015820:Cadherins; D003598:Cytoskeletal Proteins; D051180:Desmoplakins; D046911:Macromolecular Substances; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin; D051185:gamma Catenin