ZFIN ID: ZDB-PUB-040830-1
Roles of Eph receptors and ephrins in segmental patterning
Xu, Q., Mellitzer, G., and Wilkinson, D.G.
Date: 2000
Source: Philosophical transactions of the Royal Society of London. Series B, Biological sciences   355(1399): 993-1002 (Review)
Registered Authors: Wilkinson, David, Xu, Qiling
Keywords: none
MeSH Terms:
  • Animals
  • Axons/physiology
  • Body Patterning/physiology*
  • Cell Adhesion
  • Cell Movement/physiology
  • Ephrin-A4
  • Ephrin-B2
  • Fetal Proteins/metabolism
  • Fetal Proteins/physiology*
  • Membrane Proteins/metabolism
  • Membrane Proteins/physiology*
  • Neural Crest/cytology
  • Receptor Protein-Tyrosine Kinases/metabolism
  • Receptor Protein-Tyrosine Kinases/physiology*
  • Receptor, EphA4
  • Receptor, EphB4
  • Receptors, Eph Family
  • Rhombencephalon/embryology
PubMed: 11128993 Full text @ Phil. Trans. Roy. Soc. Lond., Series B
Eph receptor tyrosine kinases and their membrane-bound ligands, ephrins, have key roles in patterning and morphogenesis. Interactions between these molecules are promiscuous, but largely fall into two groups: EphA receptors bind to glycosylphosphatidyl inositol-anchored ephrin-A ligands, and EphB receptors bind to transmembrane ephrin-B proteins. Ephrin-B proteins transduce signals, such that bidirectional signalling can occur upon interaction with the Eph receptor. In many tissues, there are complementary and overlapping expression domains of interacting Eph receptors and ephrins. An important role of Eph receptors and ephrins is to mediate cell contact-dependent repulsion, and this has been implicated in the pathfinding of axons and neural crest cells, and the restriction of cell intermingling between hindbrain segments. Studies in an in vitro system show that bidirectional activation is required to prevent intermingling between cell populations, whereas unidirectional activation can restrict cell communication via gap junctions. Recent work indicates that Eph receptors can also upregulate cell adhesion, but the biochemical basis of repulsion versus adhesion responses is unclear. Eph receptors and ephrins have thus emerged as key regulators that, in parallel with cell adhesion molecules, underlie the establishment and maintenance of patterns of cellular organization.