Ephrin B proteins are thought to play key roles in cellular functions as diverse as neuronal migration and blood vessel development. Ephrin B molecules expressed at the membrane surface bind to the Ephrin B family receptors on target cells during cell to cell contact. This interaction leads to cell signaling in the target cell but also generates a reverse signal in the cell expressing Ephrin B on its surface. This reverse signaling event is thought to be critical for vessel maturation and neuronal development. Importantly, tyrosine phosphorylation of Ephrin B is thought to be a critical component of this reverse signaling event. Recent work demonstrated that Tyr331 of Ephrin B was phosphorylated in HEK293 cells after stimulation by the soluble Ephrin B2 receptor tyrosine kinase.
