Receptor tyrosine kinases (RTKs) are cell surface receptors for growth factors, cytokines, and hormones. Ligand binding to the extracellular domain of an RTK induces dimerization and autophosphorylation of multiple specific intracellular tyrosine residues, in both the kinase catalytic domain, and at sites for signaling protein recruitment. The creation of binding sites for Src homology 2 (SH2) and phosphotyrosine binding (PTB) domains allows recruitment of proteins carrying these binding domains. The subsequent phosphorylation and activation of receptor-binding proteins leads to the initiation of key signal transduction pathways, including MAPK, PI-3 kinase and STAT signaling pathways.
In addition to mediating normal cellular processes, RTKs play a critical role in the development and progression of many types of cancer.
TGR has developed several assays for the interrogation of these receptors:
- phospho-EGF receptor
- phospho-Insulin receptor
- phospho-VEGF receptor 2
- phospho-ALK (p-Tyr1586, and p-Tyr1604)
- phospho-IGF-1 receptor
Many downstream targets, such as MAPK, PI-3 kinase, and STAT targets are also available.