An angiotensin II type 1 receptor activation switch patch revealed through evolutionary trace analysis.

摘要: Seven transmembrane (7TM) or G protein-coupled receptors constitute a large superfamily of cell surface sharing structural motif seven spanning alpha helices. Their activation mechanism most likely involves concerted movements the helices, but remains to be completely resolved. Evolutionary Trace (ET) analysis is computational method, which identifies clusters functionally important residues by integrating information on evolutionary residue variations with receptor structure. Combined known mutational data, ET predicted patch in cytoplasmic parts TM2, TM3, and TM6 form an switch that common all family A 7TM receptors. We tested this hypothesis rat Angiotensin II (Ang II) type 1a (AT1a) receptor. The has roles cardiovascular system, also frequently been applied as model for signaling. Six mutations: F66A, L67R, L70R, L119R, D125A, I245F were targeted putative assayed changes state their ligand binding, signaling, trafficking properties. All one mutant (that was not expressed well) displayed phenotypes associated changed state, such increased agonist affinity basal activity, promiscuous activation, constitutive internalization highlighting importance testing different signaling pathways. conclude mediates interactions maintaining inactive state. More broadly, these observations AT1 are consistent predictions generic role activation.