Notch post-translationally regulates β-catenin protein in stem and progenitor cells

Nat Cell Biol. 2011 Aug 14;13(10):1244-51. doi: 10.1038/ncb2313.

Abstract

Cellular decisions of self-renewal or differentiation arise from integration and reciprocal titration of numerous regulatory networks. Notch and Wnt/β-catenin signalling often intersect in stem and progenitor cells and regulate each other transcriptionally. The biological outcome of signalling through each pathway often depends on the context and timing as cells progress through stages of differentiation. Here, we show that membrane-bound Notch physically associates with unphosphorylated (active) β-catenin in stem and colon cancer cells and negatively regulates post-translational accumulation of active β-catenin protein. Notch-dependent regulation of β-catenin protein did not require ligand-dependent membrane cleavage of Notch or the glycogen synthase kinase-3β-dependent activity of the β-catenin destruction complex. It did, however, require the endocytic adaptor protein Numb and lysosomal activity. This study reveals a previously unrecognized function of Notch in negatively titrating active β-catenin protein levels in stem and progenitor cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation
  • Cell Proliferation
  • Colonic Neoplasms / genetics
  • Colonic Neoplasms / metabolism*
  • Embryonic Stem Cells / metabolism*
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • HT29 Cells
  • Humans
  • Immunoglobulin J Recombination Signal Sequence-Binding Protein / genetics
  • Immunoglobulin J Recombination Signal Sequence-Binding Protein / metabolism
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Knockout
  • Nerve Tissue Proteins / metabolism
  • Protein Processing, Post-Translational*
  • RNA Interference
  • Receptor, Notch1 / genetics
  • Receptor, Notch1 / metabolism*
  • Signal Transduction
  • Transfection
  • beta Catenin / deficiency
  • beta Catenin / genetics
  • beta Catenin / metabolism*

Substances

  • CTNNB1 protein, human
  • CTNNB1 protein, mouse
  • Immunoglobulin J Recombination Signal Sequence-Binding Protein
  • Membrane Proteins
  • NOTCH1 protein, human
  • Nerve Tissue Proteins
  • Notch1 protein, mouse
  • Numb protein, human
  • Numb protein, mouse
  • Rbpj protein, mouse
  • Receptor, Notch1
  • beta Catenin
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • Glycogen Synthase Kinase 3