title: The Erbin PDZ domain binds with high affinity and specificity to the carboxyl termini of delta-catenin and ARVCF.
abstract: Erbin is a recently described member of the LAP (leucine-rich repeat and PDZ domain) protein family. We used a C-terminally displayed phage peptide library to identify optimal ligands for the Erbin PDZ domain. Phage-selected peptides were type 1 PDZ ligands that bound with high affinity and specificity to the Erbin PDZ domain in vitro. These peptides most closely resembled the C-terminal PDZ domain-binding motifs of three p120-related catenins: delta-catenin, ARVCF, and p0071 (DSWV-COOH). Analysis of the interactions of the Erbin PDZ domain with synthetic peptides matching the C termini of ARVCF or delta-catenin also demonstrated specific high affinity binding. We characterized the interactions between the Erbin PDZ domain and both ARVCF and delta-catenin in vitro and in vivo. The Erbin PDZ domain co-localized and coprecipitated with ARVCF or delta-catenin complexed with beta-catenin and E/N-cadherin. Mutagenesis and peptide competition experiments showed that the association of Erbin with the cadherin-catenin complex was mediated by the interaction of its PDZ domain with the C-terminal PDZ domain-binding motifs (DSWV-COOH) of ARVCF and delta-catenin. Finally, we showed that endogenous delta-catenin and Erbin co-localized in and co-immunoprecipitated from neurons. These results suggest that delta-catenin and ARVCF may function to mediate the association of Erbin with the junctional cadherin-catenin complex. They also demonstrate that C-terminal phage-display technology can be used to predict physiologically relevant ligands for PDZ domains.
authors.affiliation: Department of Molecular Oncology, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, USA.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Laura
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Witt
authors.forename: Heike A
authors.initials: HA
authors.lastname: Held
authors.forename: Resi
authors.initials: R
authors.lastname: Gerstner
authors.forename: Kurt
authors.initials: K
authors.lastname: Deshayes
authors.forename: Michael F T
authors.initials: MF
authors.lastname: Koehler
authors.forename: Kenneth S
authors.initials: KS
authors.lastname: Kosik
authors.forename: Sachdev S
authors.initials: SS
authors.lastname: Sidhu
authors.forename: Laurence A
authors.initials: LA
authors.lastname: Lasky
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D051186:Armadillo Domain Proteins; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051177:Catenins; D015815:Cell Adhesion Molecules; D002460:Cell Line; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010750:Phosphoproteins; D011485:Protein Binding; D051381:Rats; D014162:Transfection; D000095002:Delta Catenin
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051186:Armadillo Domain Proteins; D002352:Carrier Proteins; D051177:Catenins; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; C413364:ERBIN protein, human; D008024:Ligands; D010750:Phosphoproteins; D000095002:Delta Catenin