This entry represents the SAM (sterile alpha motif) domain of the EphB1 receptors. This domain, located in the cytoplasmic region of EphB1, is a potential C-terminal protein-protein interaction domain. In human vascular endothelial cells, it appears to mediate cell-cell initiated signal transduction via the binding of the adaptor protein GRB10 (growth factor) through its SH2 domain to a conserved tyrosine that is phosphorylated []. EphB1 receptors play a role in neurogenesis, in particular in regulation of proliferation and migration of neural progenitors in the hippocampus and in corneal neovascularization []; they are involved in converting the crossed retinal projection to ipsilateral retinal projection []. They may be potential targets in angiogenesis-related disorders [].
This entry represents the ligand-binding domain found in ephrin type-B receptor 1 (EphB1). Using EphB1 knockout-mice, EphB1 has been shown to be essential to the development of long-term potentiation (LTP) [], a cellular model of synaptic plasticity, learning and memory formation [, , ].Class EphB receptors bind to transmembrane ephrin-B ligands. There are six vertebrate EhpB receptors (EphB1-6), which display promiscuous interactions with three ephrin-B ligands [].Ephrin receptors (EphRs) comprise thelargest subfamily of receptor tyrosine kinases (RTKs). EphRs contain a ligand binding domain and two fibronectin repeats extracellularly, a transmembrane segment, and a cytoplasmic tyrosine kinase domain. Binding of the ephrin ligand to EphR requires cell-cell contact since both are anchored to the plasma membrane. The resulting downstream signals occur bidirectionally in both EphR-expressing cells (forward signaling) and ephrin-expressing cells (reverse signaling) [].
