The β-catenin HMP-2 functions downstream of Src in parallel with the Wnt pathway in early embryogenesis of C. elegans

Dev Biol. 2011 Jul 15;355(2):302-12. doi: 10.1016/j.ydbio.2011.04.034. Epub 2011 May 6.

Abstract

The Wnt and Src pathways are widely used signal transduction pathways in development. β-catenin is utilized in both pathways, as a signal transducer and a component of the cadherin cell adhesion complex, respectively. A C. elegans β-catenin HMP-2 is involved in cell adhesion, but its signaling role has been unknown. Here, we report that in early embryogenesis HMP-2 acts as a signaling molecule in the Src signal. During early embryogenesis in C. elegans, the Wnt and Src pathways are redundantly involved in endoderm induction at the four-cell stage and spindle orientation in an ABar blastomere. RNAi experiments demonstrated that HMP-2 functions in the Src pathway, but in parallel with the Wnt pathway in these processes. HMP-2 localized at the cell boundaries and nuclei, and its localization at cell boundaries was negatively regulated by SRC-1. In addition, HMP-2 was Tyr-phosphorylated in a SRC-1-dependent manner in vivo. Taken together, we propose that HMP-2 functions downstream of the Src signaling pathway and contribute to endoderm induction and ABar spindle orientation, in parallel with the Wnt signaling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism*
  • Embryonic Development / physiology*
  • Fluorescent Antibody Technique
  • Indoles
  • Phosphorylation
  • Protein Kinases / metabolism*
  • RNA Interference
  • Signal Transduction / physiology*
  • Wnt Proteins / metabolism*

Substances

  • Caenorhabditis elegans Proteins
  • Cytoskeletal Proteins
  • HMP-2 protein, C elegans
  • Indoles
  • Wnt Proteins
  • DAPI
  • Protein Kinases
  • SRC-1 protein, C elegans