EPHB4 Cellular Phosphorylation Assay Service

EPHB4 Cellular Phosphorylation Assay (intracellular kinase activity assay) for compound screening and profiling in intact cells

Target Overview

Target Description

The receptor tyrosine kinase EPHB4 belongs to the family of Ephrin receptors. It is activated by binding to its membrane-bound ligand Ephrin-B2. Receptor and ligand are reciprocally expressed in venous and arterial endothelial cells and play an important role in angiogenesis. In several human tumors increased levels of the EPHB4 protein were identified, a finding that characterizes the receptor as a potential cancer target.

HGNC Reference




Cell Line


Target Expression


Assay Properties

Assay Description

Reaction Biology’s cellular EPHB4 phosphorylation assay was generated on a mouse embryonal fibroblast (MEF) background. Cells were transfected to express a full-length human EPHB4 molecule. Binding of a soluble EphrinB2/Fc Chimera activates receptor autophosphorylation via the mechanism of receptor oligomerization. After stimulation with the ligand the phospho-EPHB4 levels are quantified by Sandwich-ELISA technique. The assay is validated based on known inhibitors of EPHB4 kinase activity (see Fig. 1).


Substrate phosphorylation as a readout of intracellular kinase activity via ELISA

Screening Location

Freiburg, Germany

Further Information

More information can be found on our website Cellular Phosphorylation Assay Services.

Reference compound IC50 for EPHB4

Reference compound IC50 for EPHB4

Sorafenib is a potent inhibitor of the Ephrin-B2 induced phospho-EPHB4 signal found in the described cells. The graph shows a representative result of an experiment with Sorafenib.