Delamination of neural crest cells requires transient and reversible Wnt inhibition mediated by Dact1/2

Development. 2016 Jun 15;143(12):2194-205. doi: 10.1242/dev.134981. Epub 2016 Apr 27.

Abstract

Delamination of neural crest (NC) cells is a bona fide physiological model of epithelial-to-mesenchymal transition (EMT), a process that is influenced by Wnt/β-catenin signalling. Using two in vivo models, we show that Wnt/β-catenin signalling is transiently inhibited at the time of NC delamination. In attempting to define the mechanism underlying this inhibition, we found that the scaffold proteins Dact1 and Dact2, which are expressed in pre-migratory NC cells, are required for NC delamination in Xenopus and chick embryos, whereas they do not affect the motile properties of migratory NC cells. Dact1/2 inhibit Wnt/β-catenin signalling upstream of the transcriptional activity of T cell factor (TCF), which is required for EMT to proceed. Dact1/2 regulate the subcellular distribution of β-catenin, preventing β-catenin from acting as a transcriptional co-activator to TCF, yet without affecting its stability. Together, these data identify a novel yet important regulatory element that inhibits β-catenin signalling, which then affects NC delamination.

Keywords: Chick embryo; Dapper; Dishevelled antagonist of β-catenin; Frodo; Nuclear bodies; Xenopus embryo; β-catenin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism*
  • Animals
  • Cell Movement
  • Cell Nucleus / metabolism
  • Chick Embryo
  • Female
  • HEK293 Cells
  • Humans
  • Neural Crest / cytology*
  • Neural Crest / metabolism*
  • Subcellular Fractions / metabolism
  • Wnt Proteins / metabolism*
  • Wnt Signaling Pathway
  • Xenopus laevis / embryology
  • Xenopus laevis / metabolism
  • beta Catenin / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Wnt Proteins
  • beta Catenin