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

Nature. 2000 Aug 3;406(6795):527-32. doi: 10.1038/35020099.

Abstract

In flies and vertebrates, Armadillo/beta-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 beta-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 beta-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 beta-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 beta-catenins in adhesion and in signalling are performed by separate proteins.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Caenorhabditis elegans / metabolism*
  • Caenorhabditis elegans Proteins*
  • Cell Adhesion
  • Cell Line
  • Cloning, Molecular
  • Cytoskeletal Proteins / metabolism*
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation
  • Genes, Helminth
  • Genes, Reporter
  • Helminth Proteins / metabolism
  • High Mobility Group Proteins / metabolism*
  • Homeodomain Proteins / genetics
  • Mice
  • Molecular Sequence Data
  • Mutation
  • Proto-Oncogene Proteins / metabolism*
  • Signal Transduction*
  • Trans-Activators*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Two-Hybrid System Techniques
  • Wnt Proteins
  • Zebrafish Proteins*
  • beta Catenin

Substances

  • CTNNB1 protein, mouse
  • Caenorhabditis elegans Proteins
  • Cytoskeletal Proteins
  • DNA-Binding Proteins
  • Helminth Proteins
  • High Mobility Group Proteins
  • Homeodomain Proteins
  • Mab-5 protein, C elegans
  • Proto-Oncogene Proteins
  • Trans-Activators
  • Transcription Factors
  • Wnt Proteins
  • Zebrafish Proteins
  • bar-1 protein, C elegans
  • beta Catenin
  • pop-1 protein, C elegans

Associated data

  • GENBANK/AF013951
  • GENBANK/AF016853
  • GENBANK/AF016854
  • GENBANK/AF063646
  • GENBANK/U37532