Ephrins are a family of cell surface molecules that play important roles in various biological processes, including neurite outgrowth angiogenesis. Ephrins are divided into two classes: Ephrin-A (glycosylphosphatidylinositol-anchored) and Ephrin-B (transmembrane with PDZ-binding motif). Their interactions with Eph receptor tyrosine kinases contribute to a wide range of cellular activities, including cell adhesion, migration, and axon guidance. Ephrin-B2 on the cell surface binds to EphB4 on the surface of an adjacent cell. Binding triggers clustering and dimerization of EphB4 receptors, leading to their activation and autophosphorylation of specific tyrosine residues in the intracellular domain of EphB4. Activated EphB4 receptors then initiate a signalling cascade within the receptor-expressing cell. This cascade can involve phosphorylation of downstream signalling molecules, such as Src family kinases. In addition to forward signalling via EphB4, interactions between ephrins and their receptors also triggers reverse signalling in the ligand-expressing cell expressing Ephrin-B2. EphB4 is expressed on endothelial cells, which form the inner lining of blood vessels, whilst ephrin-B2 is expressed on perivascular cells, such as smooth muscle cells and pericytes, which surround blood vessels. This reverse signalling can influence cytoskeletal rearrangements, cell adhesion, and other cellular processes in the ligand-expressing cell. In angiogenesis, ephrins and their receptors, Eph receptors, guide endothelial cells, the constituents of blood vessels, to assemble and form functional vessels. Ephrin-Eph signalling guides the behaviour of endothelial cells during vessel sprouting, endothelial migration, and vessel network formation. During angiogenesis, Ephrin-B2 and its receptor EphB4 also have a key function in vessel sprouting. Ephrin-B2 is expressed on the surface of vessel tip cells, the specialized endothelial cells at the leading edge of growing vessel sprouts. Tip cells guide vessel elongation and navigate through tissue to connect with other blood vessels. Conversely, EphB4 is expressed on stalk cells, which follow tip cells to form the vessel trunk. Ephrin-B2's interaction with EphB4 plays a role in maintaining the correct spacing between tip and stalk cells, ensuring appropriate vessel architecture. Ephrin-Eph signaling also influences the migration of endothelial cells in other ways. Ephrin-B2 expressed on the surface of one endothelial cell can interact with EphB4 on another, leading to repulsion between cells. This repulsion helps prevent the collapse of blood vessels by preventing excessive merging or clustering of tip cells. Finally, ephrins function can intersect with the activities of other angiogenic factors, creating signalling crosstalk in angiogenesis. For example, Vascular Endothelial Growth Factor (VEGF) can induce EphB4 expression in endothelial cells. VEGF signalling activates hypoxia-inducible factor 1-alpha (HIF-1α) in normoxic conditions which binds to specific regulatory elements in the promoter region of the EphB4 gene, inducing expression. The interaction between VEGF signalling and EphB4 induction promotes endothelial cell migration, essential for vessel sprouting. We offer a wide product catalogue of research tools for investigating ephrins, including Eph receptor A2+A3+A4 antibodies, Eph receptor A7 antibodies, Ephrin A1 antibodies, Ephrin B2 antibodies, and Eph receptor A1 antibodies. Explore our full ephrins product range below and discover more, for less. Alternatively, you can explore our Eph Receptors product range.