Helix 8 of the angiotensin- II type 1A receptor interacts with phosphatidylinositol phosphates and modulates membrane insertion

Daniel J Hirst, John T-H Lee, Leonard K Pattenden, Walter Glen Thomas, Mibel Isabel Aguilar

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)

Abstract

The carboxyl-terminus of the type 1 angiotensin II receptor (AT1A) regulates receptor activation/deactivation and the amphipathic Helix 8 within the carboxyl-terminus is a high affinity interaction motif for plasma membrane lipids. We have used dual polarisation interferometry (DPI) to examine the role of phosphatidylinositdes in the specific recognition of Helix 8 in the AT1A receptor. A synthetic peptide corresponding to Leu(305) to Lys(325) (Helix 8 AT1A) discriminated between PIPs and different charges on lipid membranes. Peptide binding to PtdIns(4)P-containing bilayers caused a dramatic change in the birefringence (a measure of membrane order) of the bilayer. Kinetic modelling showed that PtdIns(4)P is held above the bilayer until the mass of bound peptide reaches a threshold, after which the peptides insert further into the bilayer. This suggests that Helix 8 can respond to the presence of PI(4)P by withdrawing from the bilayer, resulting in a functional conformational change in the receptor.
Original languageEnglish
Pages (from-to)1 - 14
Number of pages14
JournalScientific Reports
Volume5
Issue number(Art. No: 9972)
DOIs
Publication statusPublished - 2015

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