Differential Expression Patterns of Eph Receptors and Ephrin Ligands in Human Cancers

Figure 3

Eph/Ephrin Forward/Reverse Signaling and Cis-Inhibition. (a) Ephrin ligand and Eph receptors expressed on opposite cells are in trans-configuration. Both Eph receptor and ephrins activate bidirectional signaling—forward signaling with Eph receptors and reverse signaling with ephrin ligands. The activation is depicted by the presence of phosphorylated residues in the receptor. (b) Coexpression of EphA family receptor and ephrin-A family ligand on the same cell results in a cis-configuration. Such arrangement impairs Eph receptor activation and prevents trans-interaction. The inactive receptor is indicated by the lack of phosphorylated residues.

(a)

(b)