Structural Mechanisms of Voltage Sensing in G Protein-Coupled Receptors

Vickery, Owen N.; Machtens, Jan-Philipp; Tamburrino, Giulia; Seeliger, Daniel; Zachariae, Ulrich

doi:10.1016/j.str.2016.04.007

Journal Article

FZJ-2016-03981

Structural Mechanisms of Voltage Sensing in G Protein-Coupled Receptors

Vickery, O. ; Machtens, J.-P.FZJ* ; Tamburrino, G. ; Seeliger, D. ; Zachariae, U. (Corresponding author)

2016
Elsevier Science London [u.a.]

Structure 24(6), 997 - 1007 (2016) [10.1016/j.str.2016.04.007]

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Please use a persistent id in citations: http://hdl.handle.net/2128/11948 doi:10.1016/j.str.2016.04.007

Abstract: G-protein-coupled receptors (GPCRs) form the largest superfamily of membrane proteins and one-third of all drug targets in humans. A number of recent studies have reported evidence for substantial voltage regulation of GPCRs. However, the structural basis of GPCR voltage sensing has remained enigmatic. Here, we present atomistic simulations on the δ-opioid and M2 muscarinic receptors, which suggest a structural and mechanistic explanation for the observed voltage-induced functional effects. The simulations reveal that the position of an internal Na+ ion, recently detected to bind to a highly conserved aqueous pocket in receptor crystal structures, strongly responds to voltage changes. The movements give rise to gating charges in excellent agreement with previous experimental recordings. Furthermore, free energy calculations show that these rearrangements of Na+ can be induced by physiological membrane voltages. Due to its role in receptor function and signal bias, the repositioning of Na+ has important general implications for signal transduction in GPCRs.

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