2kso

Structural highlights

Disease

[EPHA2_HUMAN] Genetic variations in EPHA2 are the cause of susceptibility to cataract cortical age-related type 2 (ARCC2) [MIM:613020]. A developmental punctate opacity common in the cortex and present in most lenses. The cataract is white or cerulean, increases in number with age, but rarely affects vision.^{[1] [2]} Defects in EPHA2 are the cause of cataract posterior polar type 1 (CTPP1) [MIM:116600]. A subcapsular opacity, usually disk-shaped, located at the back of the lens. It can have a marked effect on visual acuity.^{[3] [4] [5] [6]} Note=Overexpressed in several cancer types and promotes malignancy.^[7] [SHIP2_HUMAN] Defects in INPPL1 may be a cause of susceptibility to type 2 diabetes mellitus non-insulin dependent (NIDDM) [MIM:125853].^{[8] [9]} Note=Genetic variations in INPPL1 may be a cause of susceptibility to metabolic syndrome. Metabolic syndrome is characterized by diabetes, insulin resistance, hypertension, and hypertriglyceridemia is absent.

Function

[EPHA2_HUMAN] Receptor tyrosine kinase which binds promiscuously membrane-bound ephrin-A 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. Activated by the ligand ephrin-A1/EFNA1 regulates migration, integrin-mediated adhesion, proliferation and differentiation of cells. Regulates cell adhesion and differentiation through DSG1/desmoglein-1 and inhibition of the ERK1/ERK2 (MAPK3/MAPK1, respectively) signaling pathway. May also participate in UV radiation-induced apoptosis and have a ligand-independent stimulatory effect on chemotactic cell migration. During development, may function in distinctive aspects of pattern formation and subsequently in development of several fetal tissues. Involved for instance in angiogenesis, in early hindbrain development and epithelial proliferation and branching morphogenesis during mammary gland development. Engaged by the ligand ephrin-A5/EFNA5 may regulate lens fiber cells shape and interactions and be important for lens transparency development and maintenance. With ephrin-A2/EFNA2 may play a role in bone remodeling through regulation of osteoclastogenesis and osteoblastogenesis.^{[10] [11] [12] [13] [14] [15]} [SHIP2_HUMAN] Phosphatidylinositol (PtdIns) phosphatase that specifically hydrolyzes the 5-phosphate of phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P3) to produce PtdIns(3,4)P2, thereby negatively regulating the PI3K (phosphoinositide 3-kinase) pathways. Plays a central role in regulation of PI3K-dependent insulin signaling, although the precise molecular mechanisms and signaling pathways remain unclear. While overexpression reduces both insulin-stimulated MAP kinase and Akt activation, its absence does not affect insulin signaling or GLUT4 trafficking. Confers resistance to dietary obesity. May act by regulating AKT2, but not AKT1, phosphorylation at the plasma membrane. Part of a signaling pathway that regulates actin cytoskeleton remodeling. Required for the maintenance and dynamic remodeling of actin structures as well as in endocytosis, having a major impact on ligand-induced EGFR internalization and degradation. Participates in regulation of cortical and submembraneous actin by hydrolyzing PtdIns(3,4,5)P3 thereby regulating membrane ruffling. Regulates cell adhesion and cell spreading. Required for HGF-mediated lamellipodium formation, cell scattering and spreading. Acts as a negative regulator of EPHA2 receptor endocytosis by inhibiting via PI3K-dependent Rac1 activation. Acts as a regulator of neuritogenesis by regulating PtdIns(3,4,5)P3 level and is required to form an initial protrusive pattern, and later, maintain proper neurite outgrowth. Acts as a negative regulator of the FC-gamma-RIIA receptor (FCGR2A). Mediates signaling from the FC-gamma-RIIB receptor (FCGR2B), playing a central role in terminating signal transduction from activating immune/hematopoietic cell receptor systems. Involved in EGF signaling pathway. Upon stimulation by EGF, it is recruited by EGFR and dephosphorylates PtdIns(3,4,5)P3. Plays a negative role in regulating the PI3K-PKB pathway, possibly by inhibiting PKB activity. Down-regulates Fc-gamma-R-mediated phagocytosis in macrophages independently of INPP5D/SHIP1. In macrophages, down-regulates NF-kappa-B-dependent gene transcription by regulating macrophage colony-stimulating factor (M-CSF)-induced signaling. May also hydrolyze PtdIns(1,3,4,5)P4, and could thus affect the levels of the higher inositol polyphosphates like InsP6.^{[16] [17] [18] [19] [20] [21] [22] [23]}

See Also

• Ephrin receptor

References

1. ↑ Miao H, Li DQ, Mukherjee A, Guo H, Petty A, Cutter J, Basilion JP, Sedor J, Wu J, Danielpour D, Sloan AE, Cohen ML, Wang B. EphA2 mediates ligand-dependent inhibition and ligand-independent promotion of cell migration and invasion via a reciprocal regulatory loop with Akt. Cancer Cell. 2009 Jul 7;16(1):9-20. doi: 10.1016/j.ccr.2009.04.009. PMID:19573808 doi:10.1016/j.ccr.2009.04.009
2. ↑ Jun G, Guo H, Klein BE, Klein R, Wang JJ, Mitchell P, Miao H, Lee KE, Joshi T, Buck M, Chugha P, Bardenstein D, Klein AP, Bailey-Wilson JE, Gong X, Spector TD, Andrew T, Hammond CJ, Elston RC, Iyengar SK, Wang B. EPHA2 is associated with age-related cortical cataract in mice and humans. PLoS Genet. 2009 Jul;5(7):e1000584. doi: 10.1371/journal.pgen.1000584. Epub 2009 , Jul 31. PMID:19649315 doi:10.1371/journal.pgen.1000584
3. ↑ Miao H, Li DQ, Mukherjee A, Guo H, Petty A, Cutter J, Basilion JP, Sedor J, Wu J, Danielpour D, Sloan AE, Cohen ML, Wang B. EphA2 mediates ligand-dependent inhibition and ligand-independent promotion of cell migration and invasion via a reciprocal regulatory loop with Akt. Cancer Cell. 2009 Jul 7;16(1):9-20. doi: 10.1016/j.ccr.2009.04.009. PMID:19573808 doi:10.1016/j.ccr.2009.04.009
4. ↑ Shiels A, Bennett TM, Knopf HL, Maraini G, Li A, Jiao X, Hejtmancik JF. The EPHA2 gene is associated with cataracts linked to chromosome 1p. Mol Vis. 2008;14:2042-55. Epub 2008 Nov 12. PMID:19005574
5. ↑ Zhang T, Hua R, Xiao W, Burdon KP, Bhattacharya SS, Craig JE, Shang D, Zhao X, Mackey DA, Moore AT, Luo Y, Zhang J, Zhang X. Mutations of the EPHA2 receptor tyrosine kinase gene cause autosomal dominant congenital cataract. Hum Mutat. 2009 May;30(5):E603-11. doi: 10.1002/humu.20995. PMID:19306328 doi:10.1002/humu.20995
6. ↑ Park JE, Son AI, Hua R, Wang L, Zhang X, Zhou R. Human cataract mutations in EPHA2 SAM domain alter receptor stability and function. PLoS One. 2012;7(5):e36564. doi: 10.1371/journal.pone.0036564. Epub 2012 May 3. PMID:22570727 doi:10.1371/journal.pone.0036564
7. ↑ Miao H, Li DQ, Mukherjee A, Guo H, Petty A, Cutter J, Basilion JP, Sedor J, Wu J, Danielpour D, Sloan AE, Cohen ML, Wang B. EphA2 mediates ligand-dependent inhibition and ligand-independent promotion of cell migration and invasion via a reciprocal regulatory loop with Akt. Cancer Cell. 2009 Jul 7;16(1):9-20. doi: 10.1016/j.ccr.2009.04.009. PMID:19573808 doi:10.1016/j.ccr.2009.04.009
8. ↑ Marion E, Kaisaki PJ, Pouillon V, Gueydan C, Levy JC, Bodson A, Krzentowski G, Daubresse JC, Mockel J, Behrends J, Servais G, Szpirer C, Kruys V, Gauguier D, Schurmans S. The gene INPPL1, encoding the lipid phosphatase SHIP2, is a candidate for type 2 diabetes in rat and man. Diabetes. 2002 Jul;51(7):2012-7. PMID:12086927
9. ↑ Kagawa S, Sasaoka T, Yaguchi S, Ishihara H, Tsuneki H, Murakami S, Fukui K, Wada T, Kobayashi S, Kimura I, Kobayashi M. Impact of SRC homology 2-containing inositol 5'-phosphatase 2 gene polymorphisms detected in a Japanese population on insulin signaling. J Clin Endocrinol Metab. 2005 May;90(5):2911-9. Epub 2005 Feb 1. PMID:15687335 doi:jc.2004-1724
10. ↑ Miao H, Burnett E, Kinch M, Simon E, Wang B. Activation of EphA2 kinase suppresses integrin function and causes focal-adhesion-kinase dephosphorylation. Nat Cell Biol. 2000 Feb;2(2):62-9. PMID:10655584 doi:10.1038/35000008
11. ↑ Tanaka M, Kamata R, Sakai R. EphA2 phosphorylates the cytoplasmic tail of Claudin-4 and mediates paracellular permeability. J Biol Chem. 2005 Dec 23;280(51):42375-82. Epub 2005 Oct 18. PMID:16236711 doi:10.1074/jbc.M503786200
12. ↑ Zhang G, Njauw CN, Park JM, Naruse C, Asano M, Tsao H. EphA2 is an essential mediator of UV radiation-induced apoptosis. Cancer Res. 2008 Mar 15;68(6):1691-6. doi: 10.1158/0008-5472.CAN-07-2372. PMID:18339848 doi:10.1158/0008-5472.CAN-07-2372
13. ↑ Miao H, Li DQ, Mukherjee A, Guo H, Petty A, Cutter J, Basilion JP, Sedor J, Wu J, Danielpour D, Sloan AE, Cohen ML, Wang B. EphA2 mediates ligand-dependent inhibition and ligand-independent promotion of cell migration and invasion via a reciprocal regulatory loop with Akt. Cancer Cell. 2009 Jul 7;16(1):9-20. doi: 10.1016/j.ccr.2009.04.009. PMID:19573808 doi:10.1016/j.ccr.2009.04.009
14. ↑ Hiramoto-Yamaki N, Takeuchi S, Ueda S, Harada K, Fujimoto S, Negishi M, Katoh H. Ephexin4 and EphA2 mediate cell migration through a RhoG-dependent mechanism. J Cell Biol. 2010 Aug 9;190(3):461-77. doi: 10.1083/jcb.201005141. Epub 2010 Aug , 2. PMID:20679435 doi:10.1083/jcb.201005141
15. ↑ Lin S, Gordon K, Kaplan N, Getsios S. Ligand targeting of EphA2 enhances keratinocyte adhesion and differentiation via desmoglein 1. Mol Biol Cell. 2010 Nov 15;21(22):3902-14. doi: 10.1091/mbc.E10-03-0242. Epub, 2010 Sep 22. PMID:20861311 doi:10.1091/mbc.E10-03-0242
16. ↑ Habib T, Hejna JA, Moses RE, Decker SJ. Growth factors and insulin stimulate tyrosine phosphorylation of the 51C/SHIP2 protein. J Biol Chem. 1998 Jul 17;273(29):18605-9. PMID:9660833
17. ↑ Pesesse X, Dewaste V, De Smedt F, Laffargue M, Giuriato S, Moreau C, Payrastre B, Erneux C. The Src homology 2 domain containing inositol 5-phosphatase SHIP2 is recruited to the epidermal growth factor (EGF) receptor and dephosphorylates phosphatidylinositol 3,4,5-trisphosphate in EGF-stimulated COS-7 cells. J Biol Chem. 2001 Jul 27;276(30):28348-55. Epub 2001 May 10. PMID:11349134 doi:10.1074/jbc.M103537200
18. ↑ Dyson JM, O'Malley CJ, Becanovic J, Munday AD, Berndt MC, Coghill ID, Nandurkar HH, Ooms LM, Mitchell CA. The SH2-containing inositol polyphosphate 5-phosphatase, SHIP-2, binds filamin and regulates submembraneous actin. J Cell Biol. 2001 Dec 10;155(6):1065-79. Epub 2001 Dec 10. PMID:11739414 doi:10.1083/jcb.200104005
19. ↑ Prasad N, Topping RS, Decker SJ. Src family tyrosine kinases regulate adhesion-dependent tyrosine phosphorylation of 5'-inositol phosphatase SHIP2 during cell attachment and spreading on collagen I. J Cell Sci. 2002 Oct 1;115(Pt 19):3807-15. PMID:12235291
20. ↑ Dyson JM, Munday AD, Kong AM, Huysmans RD, Matzaris M, Layton MJ, Nandurkar HH, Berndt MC, Mitchell CA. SHIP-2 forms a tetrameric complex with filamin, actin, and GPIb-IX-V: localization of SHIP-2 to the activated platelet actin cytoskeleton. Blood. 2003 Aug 1;102(3):940-8. Epub 2003 Apr 3. PMID:12676785 doi:10.1182/blood-2002-09-2897
21. ↑ Pengal RA, Ganesan LP, Fang H, Marsh CB, Anderson CL, Tridandapani S. SHIP-2 inositol phosphatase is inducibly expressed in human monocytes and serves to regulate Fcgamma receptor-mediated signaling. J Biol Chem. 2003 Jun 20;278(25):22657-63. Epub 2003 Apr 10. PMID:12690104 doi:10.1074/jbc.M302907200
22. ↑ Prasad NK, Decker SJ. SH2-containing 5'-inositol phosphatase, SHIP2, regulates cytoskeleton organization and ligand-dependent down-regulation of the epidermal growth factor receptor. J Biol Chem. 2005 Apr 1;280(13):13129-36. Epub 2005 Jan 24. PMID:15668240 doi:M410289200
23. ↑ Zhuang G, Hunter S, Hwang Y, Chen J. Regulation of EphA2 receptor endocytosis by SHIP2 lipid phosphatase via phosphatidylinositol 3-Kinase-dependent Rac1 activation. J Biol Chem. 2007 Jan 26;282(4):2683-94. Epub 2006 Nov 29. PMID:17135240 doi:M608509200