Distinct β -catenins mediate adhesion and signalling functions in C. elegans

• Published in: Nature (London) 2000-08, Vol.406 (6795), p.527-532
• Main Authors: Korswagen, Hendrik C, Herman, Michael A, Clevers, Hans C
• Format: Article
• Language: English
• Subjects: Adhesion; Animals; Animals, Genetically Modified; b-catenins; BAR-1 protein; beta Catenin; Biological and medical sciences; Caenorhabditis elegans; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins; Cell Adhesion; Cell interactions, adhesion; Cell Line; Cell physiology; Cloning, Molecular; Cytoskeletal Proteins - metabolism; Deoxyribonucleic acid; DNA; DNA-Binding Proteins - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; Genes; Genes, Helminth; Genes, Reporter; Helminth Proteins - metabolism; High Mobility Group Proteins - metabolism; HMP-2 protein; HMR-1 protein; Homeodomain Proteins - genetics; Humanities and Social Sciences; letter; Mice; Molecular and cellular biology; Molecular Sequence Data; multidisciplinary; Mutation; POP-1 protein; Proteins; Proto-Oncogene Proteins - metabolism; Science; Signal Transduction; Trans-Activators; Transcription Factors - genetics; Transcription Factors - metabolism; Two-Hybrid System Techniques; Vertebrates; Wnt gene; Wnt Proteins; Worms; WRM-1 protein; Zebrafish Proteins
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/35020099

In flies and vertebrates, Armadillo/β-catenin forms a complex with Tcf/Lef-1 transcription factors, serving as an essential co-activator to mediate Wnt signalling. It also associates with cadherins to mediate adhesion. In Caenorhabditis elegans, three putative β-catenin homologues have been identified: WRM-1, BAR-1 and HMP-2. WRM-1 and the Tcf homologue POP-1 mediate Wnt signalling by a mechanism that has challenged current views of the Wnt pathway. Here we show that BAR-1 is the only β-catenin homologue that interacts directly with POP-1. BAR-1 mediates Wnt signalling by forming a BAR-1/POP-1 bipartite transcription factor that activates expression of Wnt target genes such as the Hox gene mab-5. HMP-2 is the only β-catenin homologue that interacts with the single cadherin of C. elegans, HMR-1. We conclude that a canonical Wnt pathway exists in C. elegans. Furthermore, our analysis shows that the functions of C. elegans β-catenins in adhesion and in signalling are performed by separate proteins.