1shw

Structural highlights

Function

[EFNA5_MOUSE] Cell surface GPI-bound ligand for Eph receptors, a family of receptor tyrosine kinases which are crucial for migration, repulsion and adhesion during neuronal, vascular and epithelial development. Binds promiscuously Eph receptors residing on adjacent cells, leading to contact-dependent bidirectional signaling into neighboring cells. The signaling pathway downstream of the receptor is referred to as forward signaling while the signaling pathway downstream of the ephrin ligand is referred to as reverse signaling. Induces compartmentalized signaling within a caveolae-like membrane microdomain when bound to the extracellular domain of its cognate receptor. This signaling event requires the activity of the Fyn tyrosine kinase. Activates the EPHA3 receptor to regulate cell-cell adhesion and cytoskeletal organization. With the receptor EPHA2 may regulate lens fiber cells shape and interactions and be important for lens transparency maintenance. May function actively to stimulate axon fasciculation. The interaction of EFNA5 with EPHA5 also mediates communication between pancreatic islet cells to regulate glucose-stimulated insulin secretion. Cognate/functional ligand for EPHA7, their interaction regulates brain development modulating cell-cell adhesion and repulsion.^{[1] [2] [3] [4]} [EPHB2_MOUSE] Receptor tyrosine kinase which binds promiscuously transmembrane ephrin-B family ligands residing on adjacent cells, leading to contact-dependent bidirectional signaling into neighboring cells. The signaling pathway downstream of the receptor is referred to as forward signaling while the signaling pathway downstream of the ephrin ligand is referred to as reverse signaling. Functions in axon guidance during development. Involved in the guidance of commissural axons, that form a major interhemispheric connection between the 2 temporal lobes of the cerebral cortex. Also involved in guidance of contralateral inner ear efferent growth cones at the midline and of retinal ganglion cell axons to the optic disk. Beside axon guidance, also regulates dendritic spines development and maturation and stimulates the formation of excitatory synapses. Upon activation by EFNB1, abolishes the ARHGEF15-mediated negative regulation on excitatory synapse formation. Controls other aspects of development including angiogenesis, palate development and in inner ear development through regulation of endolymph production. Forward and reverse signaling through the EFNB2/EPHB2 complex regulate movement and adhesion of cells that tubularize the urethra and septate the cloaca. May function as a tumor suppressor.^{[5] [6] [7] [8] [9] [10] [11]}

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

See Also

• Ephrin
• Ephrin receptor 3D structures

References

1. ↑ Park S, Sanchez MP. The Eek receptor, a member of the Eph family of tyrosine protein kinases, can be activated by three different Eph family ligands. Oncogene. 1997 Feb 6;14(5):533-42. PMID:9053851 doi:http://dx.doi.org/10.1038/sj.onc.1200857
2. ↑ Holmberg J, Clarke DL, Frisen J. Regulation of repulsion versus adhesion by different splice forms of an Eph receptor. Nature. 2000 Nov 9;408(6809):203-6. PMID:11089974 doi:http://dx.doi.org/10.1038/35041577
3. ↑ Konstantinova I, Nikolova G, Ohara-Imaizumi M, Meda P, Kucera T, Zarbalis K, Wurst W, Nagamatsu S, Lammert E. EphA-Ephrin-A-mediated beta cell communication regulates insulin secretion from pancreatic islets. Cell. 2007 Apr 20;129(2):359-70. PMID:17448994 doi:http://dx.doi.org/10.1016/j.cell.2007.02.044
4. ↑ Cooper MA, Son AI, Komlos D, Sun Y, Kleiman NJ, Zhou R. Loss of ephrin-A5 function disrupts lens fiber cell packing and leads to cataract. Proc Natl Acad Sci U S A. 2008 Oct 28;105(43):16620-5. doi:, 10.1073/pnas.0808987105. Epub 2008 Oct 23. PMID:18948590 doi:http://dx.doi.org/10.1073/pnas.0808987105
5. ↑ Henkemeyer M, Orioli D, Henderson JT, Saxton TM, Roder J, Pawson T, Klein R. Nuk controls pathfinding of commissural axons in the mammalian central nervous system. Cell. 1996 Jul 12;86(1):35-46. PMID:8689685
6. ↑ Orioli D, Henkemeyer M, Lemke G, Klein R, Pawson T. Sek4 and Nuk receptors cooperate in guidance of commissural axons and in palate formation. EMBO J. 1996 Nov 15;15(22):6035-49. PMID:8947026
7. ↑ Adams RH, Wilkinson GA, Weiss C, Diella F, Gale NW, Deutsch U, Risau W, Klein R. Roles of ephrinB ligands and EphB receptors in cardiovascular development: demarcation of arterial/venous domains, vascular morphogenesis, and sprouting angiogenesis. Genes Dev. 1999 Feb 1;13(3):295-306. PMID:9990854
8. ↑ Cowan CA, Yokoyama N, Bianchi LM, Henkemeyer M, Fritzsch B. EphB2 guides axons at the midline and is necessary for normal vestibular function. Neuron. 2000 May;26(2):417-30. PMID:10839360
9. ↑ Henkemeyer M, Itkis OS, Ngo M, Hickmott PW, Ethell IM. Multiple EphB receptor tyrosine kinases shape dendritic spines in the hippocampus. J Cell Biol. 2003 Dec 22;163(6):1313-26. PMID:14691139 doi:http://dx.doi.org/10.1083/jcb.200306033
10. ↑ Dravis C, Yokoyama N, Chumley MJ, Cowan CA, Silvany RE, Shay J, Baker LA, Henkemeyer M. Bidirectional signaling mediated by ephrin-B2 and EphB2 controls urorectal development. Dev Biol. 2004 Jul 15;271(2):272-90. PMID:15223334 doi:http://dx.doi.org/10.1016/j.ydbio.2004.03.027
11. ↑ Margolis SS, Salogiannis J, Lipton DM, Mandel-Brehm C, Wills ZP, Mardinly AR, Hu L, Greer PL, Bikoff JB, Ho HY, Soskis MJ, Sahin M, Greenberg ME. EphB-mediated degradation of the RhoA GEF Ephexin5 relieves a developmental brake on excitatory synapse formation. Cell. 2010 Oct 29;143(3):442-55. doi: 10.1016/j.cell.2010.09.038. PMID:21029865 doi:http://dx.doi.org/10.1016/j.cell.2010.09.038
12. ↑ Himanen JP, Chumley MJ, Lackmann M, Li C, Barton WA, Jeffrey PD, Vearing C, Geleick D, Feldheim DA, Boyd AW, Henkemeyer M, Nikolov DB. Repelling class discrimination: ephrin-A5 binds to and activates EphB2 receptor signaling. Nat Neurosci. 2004 May;7(5):501-9. Epub 2004 Apr 25. PMID:15107857 doi:10.1038/nn1237