TIE2 Cellular Phosphorylation Assay (intracellular kinase activity assay) for compound screening and profiling in intact cells
The angiopoietin (Ang)-Tie ligand-receptor system has a key role in regulating vascular integrity and quiescence. Besides its role in angiogenesis it is an important regulator in numerous diseases including inflammation. Ang-1-mediated Tie2 activation is required to maintain the quiescent resting state of the endothelium. In contrast, Ang-2 destabilizes the quiescent endothelium and primes it to respond to exogenous stimuli, thereby facilitating the activities of inflammatory and angiogenic cytokines. Intriguingly, Ang-2 is expressed weakly by the resting endothelium but becomes strongly upregulated following endothelial activation. Moreover, endothelial cells store Ang-2 in Weibel-Palade bodies from where it can be made available quickly following stimulation, suggesting a role of Ang-2 in controlling rapid vascular adaptive processes. This suggests that Ang-2 functions as a built-in switch controlling the transition of the resting quiescent endothelium towards the activated responsive endothelium (Trends Immunol. 2006 27, p552-8).
VMCM, TIE-2, VMCM1, CD202B
CHO cells have been stably transfected to overexpress full length human TIE2. Stimulation of these cells with
sodium orthovanadate results in a robust receptor autophosphorylation. Compounds are preincubated before cell stimulation to allow thorough target binding. Stimulation conditions are optimized to determine dose-related inhibition of the phospho-TIE2 signal, which is subsequently quantified by Sandwich-ELISA technique. The assay is validated based on known inhibitors of TIE2 kinase activity (see Fig. 1).
Substrate phosphorylation as a readout of intracellular kinase activity via ELISA
More information can be found on our website Cellular Phosphorylation Assay Services.
Reference compound IC50 for TIE2
Sorafenib is a potent inhibitor of TIE2 phosphorylation with highly reproducible IC50 values. The graph shows a representative result.