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Gene Review

Epha1  -  Eph receptor A1

Mus musculus

Synonyms: 5730453L17Rik, AL033318, Embryonic stem cell kinase, Eph, Ephrin type-A receptor 1, ...
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Disease relevance of Epha1


High impact information on Epha1

  • Here we report that mural cells require ephrin-B2, a ligand for Eph receptor tyrosine kinases, for normal association with small-diameter blood vessels (microvessels) [6].
  • The association of ephexin with Eph receptors constitutes a molecular link between Eph receptors and the actin cytoskeleton and provides a novel mechanism for achieving highly localized regulation of growth cone motility [7].
  • We report the cloning and characterization of ephexin, a novel Eph receptor-interacting protein that is a member of the Dbl family of guanine nucleotide exchange factors (GEFs) for Rho GTPases [7].
  • The Eph receptor tyrosine kinase family is regulated by autophosphorylation within the juxtamembrane region and the kinase activation segment [8].
  • Eph receptors transduce short-range repulsive signals for axon guidance by modulating actin dynamics within growth cones [7].

Biological context of Epha1

  • This study investigated the potential role of Eph-related molecules during very early embryonic development by examining their expression in embryonic stem (ES) cells and embryoid bodies differentiated from ES cells in vitro [9].
  • In the latter, Eph receptors and their class-A (GPI-anchored) and class-B (transmembrane) ephrin ligands control cell migration and axon-pathfinding, help establish regional patterns and act as labels for cell positioning [10].
  • These expression patterns define previously unknown developmental units and suggest that Eph family proteins may contribute to cerebellar morphogenesis [11].
  • This loop, which is conserved within but not between Eph RTK subclasses, packs against the concave beta-sandwich surface near positions at which missense mutations cause signalling defects, localizing the ligand-binding region on the surface of the receptor [12].
  • Tyrosine phosphorylation of transmembrane ligands for Eph receptors [13].

Anatomical context of Epha1

  • However, one clone contained sequence from a novel Eph-subfamily member, which was termed embryonic stem-cell kinase or Esk [9].
  • Several receptor tyrosine kinase genes of the Eph family are segmentally expressed in the developing hindbrain [14].
  • Therefore, responses mediated through specific Eph family receptors (ELK and Eck) are discriminated by endothelial cells from different vascular bed sources [15].
  • Bidirectional signals mediated by Eph receptor tyrosine kinases and their membrane-bound ligands, ephrins, play pivotal roles in the formation of neural networks by induction of both collapse and elongation of neurites [16].
  • Binding of these ligands to Eph-related receptors did not, however, elicit measurable biological signals in cultured cells [17].

Associations of Epha1 with chemical compounds

  • Characterization of the Epha1 receptor tyrosine kinase: expression in epithelial tissues [18].
  • Biochemical analyses revealed that Ptpro dephosphorylates a phosphotyrosine residue conserved in the juxtamembrane region, which is required for the activation and signal transmission of Eph receptors [19].
  • During the past year, Eph receptors have been shown to associate with glutamate receptors in excitatory neurons, suggesting a role in synapse formation or function [20].
  • An Eph receptor regulates integrin activity through R-Ras [21].

Regulatory relationships of Epha1

  • We conclude that specific members of the Eph/ephrin family are expressed in embryonic pancreas according to a dynamic temporal and regional pattern [10].
  • We show that in the developing mouse cerebellar cortex, members of the Eph receptor gene family are expressed in mediolaterally alternating Purkinje cell segments [22].

Other interactions of Epha1

  • Together with our previous finding that Sek (Sek-1) is expressed in r3 and r5 (Gilardi-Hebenstreit et al., 1992; Nieto et al., 1992), these data indicate that members of the Eph family of RTKs may co-operate in the segmental patterning of the hindbrain [14].
  • Expression analysis of the Epha1 receptor tyrosine kinase and its high-affinity ligands Efna1 and Efna3 during early mouse development [23].
  • In this study, we have isolated a full-length cDNA, encoding the mouse homologue of a previous partially characterized Eek protein, a member of Eph receptor tyrosine kinase family [24].
  • Binding experiments on whole pancreas demonstrated the presence of functional Eph receptors [10].
  • Juxtamembrane tyrosine residues couple the Eph family receptor EphB2/Nuk to specific SH2 domain proteins in neuronal cells [1].

Analytical, diagnostic and therapeutic context of Epha1

  • Here we have identified the Eph and ephrin genes that are expressed in mouse embryonic pancreas, as detected by RT-PCR analysis [10].
  • Immunohistochemistry demonstrated that the expression of Eph A1 on endometrial epithelial cells and ephrin A1 and A3 expression on embryos decreased at implantation sites [25].
  • The Eph family of receptor tyrosine kinases has been implicated in many developmental patterning processes, including cell segregation, cell migration, and axon guidance [26].
  • To examine the potential scope of action for these genes in the nervous system, we have used in situ hybridization to study the mRNA expression of ephrins (B1, B2, and B3) and Eph receptors (B1, B2, B3, A4) in neonatal and adult mice [27].
  • Abnormal topographic maps are reported in a knock-in experiment with elevated density of Eph receptors and a knock-out experiment lacking ephrin ligands using gene-targeting technology [28].


  1. Juxtamembrane tyrosine residues couple the Eph family receptor EphB2/Nuk to specific SH2 domain proteins in neuronal cells. Holland, S.J., Gale, N.W., Gish, G.D., Roth, R.A., Songyang, Z., Cantley, L.C., Henkemeyer, M., Yancopoulos, G.D., Pawson, T. EMBO J. (1997) [Pubmed]
  2. Soluble Eph A receptors inhibit tumor angiogenesis and progression in vivo. Brantley, D.M., Cheng, N., Thompson, E.J., Lin, Q., Brekken, R.A., Thorpe, P.E., Muraoka, R.S., Cerretti, D.P., Pozzi, A., Jackson, D., Lin, C., Chen, J. Oncogene (2002) [Pubmed]
  3. The ephrin-A1 ligand and its receptor, EphA2, are expressed during tumor neovascularization. Ogawa, K., Pasqualini, R., Lindberg, R.A., Kain, R., Freeman, A.L., Pasquale, E.B. Oncogene (2000) [Pubmed]
  4. Diverse roles for the Eph family of receptor tyrosine kinases in carcinogenesis. Nakamoto, M., Bergemann, A.D. Microsc. Res. Tech. (2002) [Pubmed]
  5. Proangiogenic Role of ephrinB1/EphB1 in Basic Fibroblast Growth Factor-Induced Corneal Angiogenesis. Kojima, T., Chang, J.H., Azar, D.T. Am. J. Pathol. (2007) [Pubmed]
  6. Ephrin-B2 controls cell motility and adhesion during blood-vessel-wall assembly. Foo, S.S., Turner, C.J., Adams, S., Compagni, A., Aubyn, D., Kogata, N., Lindblom, P., Shani, M., Zicha, D., Adams, R.H. Cell (2006) [Pubmed]
  7. EphA receptors regulate growth cone dynamics through the novel guanine nucleotide exchange factor ephexin. Shamah, S.M., Lin, M.Z., Goldberg, J.L., Estrach, S., Sahin, M., Hu, L., Bazalakova, M., Neve, R.L., Corfas, G., Debant, A., Greenberg, M.E. Cell (2001) [Pubmed]
  8. Structural basis for autoinhibition of the Ephb2 receptor tyrosine kinase by the unphosphorylated juxtamembrane region. Wybenga-Groot, L.E., Baskin, B., Ong, S.H., Tong, J., Pawson, T., Sicheri, F. Cell (2001) [Pubmed]
  9. Embryonic stem cells express multiple Eph-subfamily receptor tyrosine kinases. Lickliter, J.D., Smith, F.M., Olsson, J.E., Mackwell, K.L., Boyd, A.W. Proc. Natl. Acad. Sci. U.S.A. (1996) [Pubmed]
  10. Eph receptors and their ephrin ligands are expressed in developing mouse pancreas. van Eyll, J.M., Passante, L., Pierreux, C.E., Lemaigre, F.P., Vanderhaeghen, P., Rousseau, G.G. Gene Expr. Patterns (2006) [Pubmed]
  11. Eph receptors and ephrins demarcate cerebellar lobules before and during their formation. Rogers, J.H., Ciossek, T., Menzel, P., Pasquale, E.B. Mech. Dev. (1999) [Pubmed]
  12. Crystal structure of the ligand-binding domain of the receptor tyrosine kinase EphB2. Himanen, J.P., Henkemeyer, M., Nikolov, D.B. Nature (1998) [Pubmed]
  13. Tyrosine phosphorylation of transmembrane ligands for Eph receptors. Brückner, K., Pasquale, E.B., Klein, R. Science (1997) [Pubmed]
  14. Several receptor tyrosine kinase genes of the Eph family are segmentally expressed in the developing hindbrain. Becker, N., Seitanidou, T., Murphy, P., Mattéi, M.G., Topilko, P., Nieto, M.A., Wilkinson, D.G., Charnay, P., Gilardi-Hebenstreit, P. Mech. Dev. (1994) [Pubmed]
  15. ELK and LERK-2 in developing kidney and microvascular endothelial assembly. Daniel, T.O., Stein, E., Cerretti, D.P., St John, P.L., Robert, B., Abrahamson, D.R. Kidney Int. Suppl. (1996) [Pubmed]
  16. Tiam1 mediates neurite outgrowth induced by ephrin-B1 and EphA2. Tanaka, M., Ohashi, R., Nakamura, R., Shinmura, K., Kamo, T., Sakai, R., Sugimura, H. EMBO J. (2004) [Pubmed]
  17. Membrane-bound LERK2 ligand can signal through three different Eph-related receptor tyrosine kinases. Brambilla, R., Schnapp, A., Casagranda, F., Labrador, J.P., Bergemann, A.D., Flanagan, J.G., Pasquale, E.B., Klein, R. EMBO J. (1995) [Pubmed]
  18. Characterization of the Epha1 receptor tyrosine kinase: expression in epithelial tissues. Coulthard, M.G., Lickliter, J.D., Subanesan, N., Chen, K., Webb, G.C., Lowry, A.J., Koblar, S., Bottema, C.D., Boyd, A.W. Growth Factors (2001) [Pubmed]
  19. Eph receptors are negatively controlled by protein tyrosine phosphatase receptor type O. Shintani, T., Ihara, M., Sakuta, H., Takahashi, H., Watakabe, I., Noda, M. Nat. Neurosci. (2006) [Pubmed]
  20. Excitatory Eph receptors and adhesive ephrin ligands. Klein, R. Curr. Opin. Cell Biol. (2001) [Pubmed]
  21. An Eph receptor regulates integrin activity through R-Ras. Zou, J.X., Wang, B., Kalo, M.S., Zisch, A.H., Pasquale, E.B., Ruoslahti, E. Proc. Natl. Acad. Sci. U.S.A. (1999) [Pubmed]
  22. EphA4 is not required for Purkinje cell compartmentation. Karam, S.D., Dottori, M., Ogawa, K., Henderson, J.T., Boyd, A.W., Pasquale, E.B., Bothwell, M. Brain Res. Dev. Brain Res. (2002) [Pubmed]
  23. Expression analysis of the Epha1 receptor tyrosine kinase and its high-affinity ligands Efna1 and Efna3 during early mouse development. Duffy, S.L., Steiner, K.A., Tam, P.P., Boyd, A.W. Gene Expr. Patterns (2006) [Pubmed]
  24. The Eek receptor, a member of the Eph family of tyrosine protein kinases, can be activated by three different Eph family ligands. Park, S., Sánchez, M.P. Oncogene (1997) [Pubmed]
  25. Eph-ephrin A system regulates murine blastocyst attachment and spreading. Fujii, H., Tatsumi, K., Kosaka, K., Yoshioka, S., Fujiwara, H., Fujii, S. Dev. Dyn. (2006) [Pubmed]
  26. A novel signaling intermediate, SHEP1, directly couples Eph receptors to R-Ras and Rap1A. Dodelet, V.C., Pazzagli, C., Zisch, A.H., Hauser, C.A., Pasquale, E.B. J. Biol. Chem. (1999) [Pubmed]
  27. mRNA expression of ephrins and Eph receptor tyrosine kinases in the neonatal and adult mouse central nervous system. Liebl, D.J., Morris, C.J., Henkemeyer, M., Parada, L.F. J. Neurosci. Res. (2003) [Pubmed]
  28. Competition between retinal ganglion axons for targets under the servomechanism model explains abnormal retinocollicular projection of Eph receptor-overexpressing or ephrin-lacking mice. Honda, H. J. Neurosci. (2003) [Pubmed]
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