Ephrin B4 Receptor

Accession # and Alternate nomenclature: NP_004435. HTK, EPHB4, MYK1, TYRO11

The membrane bound Ephrins are ligands for Ephrin receptor tyrosine kinases that regulate several physiological functions including long-term potentiation, cell positioning, CNS development and axonal path finding and mitogenesis etc.  Ephrins molecules exhibit the ability to send bidirectional signals following ligand-receptor interactions resulting from cell-cell contacts. Activation of Eph receptors are also shown to regulate transduction pathways important in cell cycle control as well as cell death.  There are at least 4 different kinds of Ephrin B receptors are cloned (Ephrin B1R-Ephrin B4R).  EphB receptor tyrosine kinases and ephrin-B ligands also regulate several types of cell-cell interactions during brain development, generally by modulating the cytoskeleton. EphB/ephrinB genes are expressed in the developing neural tube of early mouse embryos with distinct overlapping expression in the ventral midbrain.  The positioning of cells within the stem cell niche in the intestinal epithelium is controlled by B subclass ephrins through their interaction with EphB receptors.   Ephrin 4 ligands are also known as guidance molecule as they are mainly responsible for positioning and directing the cell migration along the villus-crypt axis in intestine.  Ephrin 4 by interacting with ephrin B4 receptors in conjunction with Wnt proteins signals and promotes remodeling of arterial environment (1).  The Ephrin B receptors are the key coordinators of the intestinal stem cell niche (2).

Ephrin B4 ligands are highly expressed in the thin walled blood vessels and the Ephrins B4 receptors are expressed on vein grafts.  Ephrin-B4 promotes vein plasticity and growth to the ligand-expressing substrates in vitro.  The function of Ephrins in the immune system has not been well studied, although some Ephrins and Ephrin receptors are expressed at high levels on certain leukocytes.  EFNB3 and its cognate receptors are expressed in peripheral T cells and monocytes/macrophages.  The role of EphR2 and EphR4 in angiogenesis and formation of arteries and veins come form findings that EphR2 marks arteries but not veins and conversely, the EphR4 labels exclusively the veins (3).  . 

The EphR4-selective antibodies were generated against highly antigenic epitopes unique to EphR4 receptor tyrosine kinase that are not present on other Ephrin B Receptor.  The antibodies EphR4 are affinity purified over immobilized antigen based chromatography, and the purified immunoglobulins are stabilized in antibody stabilization buffer.  FabGennix Int. Inc., will also provide limited quantities of antigenic blocking peptides for EphR-401AP antibodies.  FabGennix International Inc. also carries antibodies that are related to other Ephrin Receptor tyrosine kinase targets and BMP proteins, a complete list of all the antibodies please visit www. FabGennix.com. FabGennix Inc. will conjugate antibodies with enzymes or fluorescent probes as custom service upon request at a reasonable cost.     

Immunogen:            Synthetic peptide taken from human Ephrin B4 receptor from within the region spanning amino acids 900-987.  The 19mer peptide is unqie to human Ephrin B4 receptor and was not present in  other proteins.  The selected peptide was post-synthetically modified to achieve highest antigenicity before coupling to carrier protein using hetero-bifunctional cross linker for immunogen preparation

Concentration:         EphR-401AP:  IgG concentration 0.55-0.62 mg/ml in antibody stabilization buffer.

Applications:           EphR-401AP antibody was tested in ELISA and western blotting applications at 1:500 dilution using PC-EphR4 samples.  Antibody dilutions for this antibody is for reference only, investigators are expected to determine the optimal conditions.  Application of this antibody in other protocols has not yet tested but it does not preclude its use in such assays.  Investigators using this antibody in protocols other than listed above can request a complimentary sample of this antibody.  WB: > 1:500; IMM & i.p pull-down assays: n.d; IHC n.d.

Reactivity:               This antibody detects a diffuse band of approximately 118kDa in PC-EphR4 Western blot positive control (Cat # PC-EphR4) samples.  The antibody does not cross reacts with other proteins of the Ephrin receptor tyrosine kinases.   

Protocols:                Standard protocol for various applications (WB; IMM and IHC) of this antibody can be obtained by calling technical service hotline.  The general information on this antibody is provided in the product specification sheet.  FabGennix Inc.  strongly recommends investigators to optimize conditions for use of this antibody in their laboratories.  

Form/Storage:         The antiserum is supplied in antibody stabilization buffer.  The affinity-purified antibodies are isolated on immobilized antigen-affinity column and supplied as stabilized product.  Store at -20^oC for long-term storage.  FabGennix Inc. does not recommend storage of very dilute antibody solutions unless they are prepared in specially formulated multi use antibody dilution buffer (Cat # DiluOBuffer).  Working solutions of antibodies in DiluOBuffer should be filtered through 0.45m filter after every use for long-term storage.

 

For research use only, not for diagnostic or therapeutic use.