Receptor tyrosine kinases

 Receptor tyrosine kinases are a common type of Enzyme Coupled receptors .Receptor tyrosine kinases have a cystolic domain with intrinsic kinase activity. The binding of extracellular ligands trigger cross phosphorylation of the tyrosine kinase domain. Proteins are then able to bind to the phosphorylated tyrosines. Proteins such as Grb2 adaptor protein (involved in the Ras pathway) which has the ability to bind to one of the phosphate groups on specific tyrosine residues. This, consequentially, recruits a Guanine nucleotide exchange factor that activate monomeric GTPases by stimulating release of GDP to allow binding of GTP.