Cell Signaling Technology

Product Pathways - Tyrosine Kinase / Adaptors

Phospho-EphA3 (Tyr779) (D10H1) Rabbit mAb #8862

Applications Reactivity Sensitivity MW (kDa) Isotype
W IP H (M) (R) Endogenous 135 Rabbit

Applications Key:  W=Western Blotting  IP=Immunoprecipitation
Reactivity Key:  H=Human  M=Mouse  R=Rat
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

Phospho-EphA3 (Tyr779) (D10H1) Rabbit mAb recognizes endogenous levels of EphA3 protein only when phosphorylated at Tyr779. This antibody cross-reacts with EphA2, EphA4, and EphA5 at the corresponding phosphosites.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Tyr779 of human EphA3 protein.

Western Blotting

Western Blotting

Western blot analysis of extracts from SNB19 cells, serum starved overnight and either untreated (-) or treated with ephrin-A5-Fc (100 ng/ml, 5 min; +), using Phospho-EphA3 (Tyr779) (D10H1) Rabbit mAb (upper) or EphA3/A4/A5 (D2C11) Rabbit mAb #8793 (lower).

Background

The Eph receptors are the largest known family of receptor tyrosine kinases (RTKs). They can be divided into two groups based on sequence similarity and on their preference for a subset of ligands. While EphA receptors bind to a glycosylphosphatidylinositol-anchored ephrin A ligand, EphB receptors bind to ephrin B proteins that have a transmembrane and cytoplasmic domain (1,2). Research studies have shown that Eph receptors and ligands may be involved in many diseases including cancer (3). Both ephrin A and B ligands have dual functions. As RTK ligands, ephrins stimulate the kinase activity of Eph receptors and activate signaling pathways in receptor-expressing cells. The ephrin extracellular domain is sufficient for this function as long as it is clustered (4). The second function of ephrins has been described as "reverse signaling", whereby the cytoplasmic domain becomes tyrosine phosphorylated, allowing interactions with other proteins that may activate signaling pathways in the ligand-expressing cells (5).The EphA3 receptor preferentially binds ephrin-A5. This ligand-receptor interaction stimulates EphA3 signaling, regulates cell adhesion and migration, and induces cellular morphologic responses (6-8). EphA3 plays a critical role in callosal axon guidance (9), retinotectal mapping of neurons (10), as well as cardiac cell migration and differentiation (11). Investigators have shown that somatic mutations in functional domains of EphA3 are linked to lung cancer progression (12). In addition, EphA3 expression levels have been correlated with tumor angiogenesis and progression in gastric and colorectal carcinoma (13,14).

Both Tyr602 and Tyr779 phosphorylation are involved in ephrin-A5 induced EphA3 receptor activation (15). Phosphorylated Tyr779 of the EphA3 receptor is the binding site for the SH2-domain-containing Crk adaptor, which in turn activates the small GTPase RhoA (16).

  1. Wilkinson, D.G. (2000) Int Rev Cytol 196, 177-244.
  2. Klein, R. (2001) Curr Opin Cell Biol 13, 196-203.
  3. Dodelet, V.C. and Pasquale, E.B. (2000) Oncogene 19, 5614-9.
  4. Holder, N. and Klein, R. (1999) Development 126, 2033-44.
  5. Brückner, K. et al. (1997) Science 275, 1640-3.
  6. Smith, L.M. et al. (2004) Exp Cell Res 292, 295-303.
  7. Clifford, N. et al. (2008) J Cell Biochem 105, 1250-9.
  8. Vearing, C. et al. (2005) Cancer Res 65, 6745-54.
  9. Nishikimi, M. et al. (2011) J Neurosci 31, 16251-60.
  10. Connor, R.J. et al. (1998) Dev Biol 193, 21-35.
  11. Li, Y.Y. et al. (1998) Am J Physiol 274, H331-41.
  12. Lisabeth, E.M. et al. (2012) Biochemistry 51, 1464-75.
  13. Xi, H.Q. et al. (2012) J Gastroenterol 47, 785-94.
  14. Xi, H.Q. and Zhao, P. (2011) J Clin Pathol 64, 498-503.
  15. Shi, G. et al. (2010) Cell Res 20, 1263-75.
  16. Lawrenson, I.D. et al. (2002) J Cell Sci 115, 1059-72.

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