An Angiotensin II type 1 receptor activation switch patch revealed through Evolutionary Trace analysis

Marie Mi Bonde, Rong Yao, Jian Nong Ma, Srinivasan Madabushi, Stig Haunsø, Ethan S. Burstein, Jennifer Whistler, Søren P. Sheikh, Olivier Lichtarge, Jakob Lerche Hansen

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

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

Original languageEnglish (US)
Pages (from-to)86-94
Number of pages9
JournalBiochemical Pharmacology
Volume80
Issue number1
DOIs
StatePublished - Jul 1 2010
Externally publishedYes

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Keywords

  • 7TM receptor
  • Angiotensin
  • Constitutive activity
  • Evolutionary Trace
  • GPCR

ASJC Scopus subject areas

  • Biochemistry
  • Pharmacology

Cite this

Bonde, M. M., Yao, R., Ma, J. N., Madabushi, S., Haunsø, S., Burstein, E. S., Whistler, J., Sheikh, S. P., Lichtarge, O., & Hansen, J. L. (2010). An Angiotensin II type 1 receptor activation switch patch revealed through Evolutionary Trace analysis. Biochemical Pharmacology, 80(1), 86-94. https://doi.org/10.1016/j.bcp.2010.03.006