This gene encodes a member of the Eph receptor family of receptor tyrosine kinase transmembrane glycoproteins. These receptors are composed of an N-terminal glycosylated ligand-binding domain, a transmembrane region and an intracellular kinase domain. They bind ligands called ephrins and are involved in diverse cellular processes including motility, division, and differentiation. A distinguishing characteristic of Eph-ephrin signaling is that both receptors and ligands are competent to transduce a signaling cascade, resulting in bidirectional signaling. This protein belongs to a subgroup of the Eph receptors called EphB. Proteins of this subgroup are distinguished from other members of the family by sequence homology and preferential binding affinity for membrane-bound ephrin-B ligands. Allelic variants are associated with prostate and brain cancer susceptibility. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2015]

EphB2: a receptor tyrosine kinase of the Eph family. A receptor for ephrin-B family members. Activated EphB2 recruits RasGAP, down-regulating the Ras-Erk signaling axis and neurite retraction. The Eph receptor tyrosine kinase family, the largest in the tyrosine kinase group, has fourteen members. They bind membrane-anchored ligands, ephrins, at sites of cell-cell contact, regulating the repulsion and adhesion of cells that underlie the establishment, maintenance, and remodeling of patterns of cellular organization. Eph signals are particularly important in regulating cell adhesion and cell migration during development, axon guidance, homeostasis and disease. EphA receptors bind to GPI-anchored ephrin-A ligands, while EphB receptors bind to ephrin-B proteins that have a transmembrane and cytoplasmic domain. Interactions between EphB receptor kinases and ephrin-B proteins transduce signals bidirectionally, signaling to both interacting cell types. Eph receptors and ephrins also regulate the adhesion of endothelial cells and are required for the remodeling of blood vessels. The ligand-activated form of EphB2 interacts with multiple proteins, including GTPase-activating protein (RASGAP) through its SH2 domain. Point mutations seen in prostate cancer. Overexpressed and required for migration of glioblastoma. Overexpressed and correlated with poor survival in breast cancer. Overexpression and loss of heterozygosity seen in colorectal cancers. Target for immunoconjugate drug therapy .Three splice-variant isoforms have been described.

Protein type: Protein kinase, TK; Kinase, protein; EC 2.7.10.1; Membrane protein, integral; Tumor suppressor; Protein kinase, tyrosine (receptor); TK group; Eph family

Chromosomal Location of Human Ortholog: 1p36.1-p35

Cellular Component: cell soma; integral to plasma membrane; axon; dendrite; extracellular region; plasma membrane; cytosol

Molecular Function: protein binding; transmembrane-ephrin receptor activity; protein-tyrosine kinase activity; axon guidance receptor activity; ATP binding; receptor binding

Biological Process: nervous system development; axon guidance; inner ear morphogenesis; peptidyl-tyrosine phosphorylation; axonal fasciculation; central nervous system projection neuron axonogenesis; learning; palate development; optic nerve morphogenesis; positive regulation of long-term neuronal synaptic plasticity; corpus callosum development; positive regulation of synaptogenesis; regulation of body fluid levels; camera-type eye morphogenesis; ephrin receptor signaling pathway; negative regulation of axonogenesis; angiogenesis; phosphorylation; urogenital system development; retinal ganglion cell axon guidance

Disease: Prostate Cancer/brain Cancer Susceptibility