The role of cholesterol on the activity and stability of neurotensin receptor 1

Abstract

Understanding the role of specific bilayer components in controlling the function of G-protein coupled receptors (GPCRs) will be a key factor in the development of novel pharmaceuticals. Cholesterol-dependence in particular has become an area of keen interest with respect to GPCR function; not least since the 2.6Å crystal structure of the β2 adrenergic receptor revealed a putative cholesterol binding motif conserved throughout class-A GPCRs. Furthermore, experimental evidence for cholesterol-dependent GPCR function has been demonstrated in a limited number of cases. This modulation of receptor function has been attributed to both direct interactions between cholesterol and receptor, and indirect effects caused by the influence of cholesterol on bilayer order and lateral pressure. Despite the widespread occurrence of cholesterol binding motifs, available experimental data on the functional involvement of cholesterol on GPCRs are currently limited to a small number of receptors. Here we investigate the role of cholesterol in the function of the neurotensin receptor 1 (NTS1) a class-A GPCR. Specifically we show how cholesterol, and the analogue cholesteryl hemisuccinate, influence activity, stability, and oligomerisation of both purified and reconstituted NTS1. The results caution against using such motifs as indicators of cholesterol-dependent GPCR activity.

Lipid-Mediated Regulation of Embedded Receptor Kinases via Parallel Allosteric Relays

“…Similar allosteric modulation of receptor function has been demonstrated in diverse membrane protein families, including G-protein-coupled receptors, receptor tyrosine kinases, and proton channels (37,39,(41)(42)(43)(44), as well as soluble cytoplasmic proteins containing lipid-targeting domains (45,46). Lipids impact the structure and function of membrane-embedded or membrane-associated proteins either through bulk effects mediated by the phospholipid bilayer or through binding of lipid molecules at specific sites (40,(47)(48)(49)(50). Interestingly, from our study, we conclude that lipid effects in EnvZ operate predominantly through peripheral interactions between nonembedded cytoplasmic domains and the lipid membrane.…”

The Molecular Basis of Oligomeric Organization of the Human M3Muscarinic Acetylcholine Receptor

“…Furthermore, although not a member of the rhodopsin-like family, the dimer of the seven TMD region of the metabotropic glutamate receptor 1 (Wu et al, 2014) shows cholesterol molecules to be situated such that they make an explicit contribution to the receptor-receptor interface. Moreover, Oates et al (2012) have shown that cholesterol influences the activity, stability, and oligomerization of the neurotensin NTS1 receptor.…”

G protein coupled receptor interactions with cholesterol deep in the membrane

“…2A). The presence of cholesterol or cholesterol hemisuccinate increases the thermal stability of many GPCRs in detergent micelles and in lipid bilayers and, in some cases, increases the affinity for agonists; the mechanisms of these effects are unclear [2,[44][45][46][47]. Addition of cholesterol to the β 2 adrenergic receptor expressed in Sf9 insect cells, where the cholesterol level is low, led to a two-fold increase in affinity for the partial inverse agonist timolol but no change for the full agonist isoproterenol [2].…”