EPHB2(redirected from EK5)
EPHB2A gene on chromosome 1p36.1-p35 that encodes a member of the ephrin-B receptor subfamily of receptor tyrosine kinases, which “promiscuously” bind membrane-bound ephrin-B family ligands residing on adjacent cells, leading to contact-dependent bidirectional signalling into neighbouring cells. EPHB2 functions in axon guidance during development, guiding commissural axons and forming a major interhemispheric connection between the two temporal lobes of the cerebral cortex. EPHB2 is also involved in the guidance of contralateral inner ear efferent growth cones at the midline, and of retinal ganglion cell axons to the optic disk. It also regulates dendritic spines development and maturation, and it stimulates the formation of excitatory synapses.
Activation of EPHB2 by EFNB1 abolishes the ARHGEF15-mediated negative regulation on excitatory synapse formation. EPHB2 also controls other aspects of development, including angiogenesis, palate development, as well as inner ear development by regulating endolymph production. It may act as a tumour suppressor.
Defects in EPHB2 have been linked to prostate cancer.