Modulation of developmental signals by endocytosis: different means and many ends

Curr Opin Cell Biol. 2003 Aug;15(4):474-81. doi: 10.1016/s0955-0674(03)00072-3.


Recent advances have highlighted the importance of endocytic processes in regulating the activity and distribution of developmental signals. Classically, signalling is downregulated by endocytosis and subsequent trafficking to lysosomes (e.g. Notch, Hedgehog, Roundabout). However, endocytosis can also have a positive role in signalling. For example, endocytosis of Delta, the ligand of Notch, is needed for activation of the signal. In the case of signalling by Hedgehog, endocytic trafficking segregates an inhibitory receptor (Patched) from the positive effector (Smoothened). Endosomes could also be the site where signalling is activated (e.g. transforming growth factor beta). Finally, endocytosis could power the transport of morphogens along epithelia.

Publication types

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

MeSH terms

  • Animals
  • Body Patterning / physiology
  • Cell Differentiation / physiology*
  • Embryo, Mammalian / cytology
  • Embryo, Mammalian / embryology*
  • Embryo, Mammalian / metabolism
  • Endocytosis / physiology*
  • Endosomes / metabolism
  • Hedgehog Proteins
  • Humans
  • Protein Transport / physiology
  • Receptor, Notch1
  • Receptors, Cell Surface / metabolism
  • Signal Transduction / physiology*
  • Trans-Activators / metabolism
  • Transcription Factors*


  • Hedgehog Proteins
  • NOTCH1 protein, human
  • Receptor, Notch1
  • Receptors, Cell Surface
  • Trans-Activators
  • Transcription Factors