scholarly journals Title: Single-molecule diffusion-based estimation of ligand effects on G protein-coupled receptors

2017 ◽  
Author(s):  
Masataka Yanagawa ◽  
Michio Hiroshima ◽  
Yuichi Togashi ◽  
Mitsuhiro Abe ◽  
Takahiro Yamashita ◽  
...  

AbstractG protein-coupled receptors (GPCRs) are major drug targets and have high potential for drug discovery. The development of a method for measuring the activities of GPCRs is essential for pharmacology and drug screening. However, it is difficult to measure the effects of a drug by monitoring the receptor on the cell surface, and changes in the concentrations of downstream signaling molecules, which depend on signaling pathway selectivity of the receptor, are used as an index of the receptor activity. Here, we show that single-molecule imaging analysis provides an alternative method for assessing ligand effects on GPCR. We monitored the dynamics of the diffusion of metabotropic glutamate receptor 3 (mGluR3), a class C GPCR, under various ligand conditions by using total internal reflection fluorescence microscopy (TIRFM). The single-molecule tracking analysis demonstrates that changes in the average diffusion coefficient of mGluR3 quantitatively reflect the ligand-dependent activity. Then, we reveal that the diffusion of receptor molecules is altered by the common physiological events associated with GPCRs, including G protein binding or accumulation in clathrin-coated pits, by inhibition experiments and dual-color single-molecule imaging analysis. We also confirm the generality of agonist-induced diffusion change in class A and B GPCRs, demonstrating that the diffusion coefficient is a good index for estimating the ligand effects on many GPCRs regardless of the phylogenetic groups, chemical properties of the ligands, and G protein-coupling selectivity.One Sentence Summary: Single-molecule imaging for evaluating ligand effects on GPCRs by monitoring the diffusion dynamics on the cell surface.

2018 ◽  
Vol 11 (548) ◽  
pp. eaao1917 ◽  
Author(s):  
Masataka Yanagawa ◽  
Michio Hiroshima ◽  
Yuichi Togashi ◽  
Mitsuhiro Abe ◽  
Takahiro Yamashita ◽  
...  

G protein–coupled receptors (GPCRs) are major drug targets. Developing a method to measure the activities of GPCRs is essential for pharmacology and drug screening. However, it is difficult to measure the effects of a drug by monitoring the receptor on the cell surface; thus, changes in the concentrations of downstream signaling molecules, which depend on the signaling pathway selectivity of the receptor, are often used as an index of receptor activity. We show that single-molecule imaging analysis provides an alternative method for assessing the effects of ligands on GPCRs. Using total internal reflection fluorescence microscopy (TIRFM), we monitored the dynamics of the diffusion of metabotropic glutamate receptor 3 (mGluR3), a class C GPCR, under various ligand conditions. Our single-molecule tracking analysis demonstrated that increases and decreases in the average diffusion coefficient of mGluR3 quantitatively reflected the ligand-dependent inactivation and activation of receptors, respectively. Through experiments with inhibitors and dual-color single-molecule imaging analysis, we found that the diffusion of receptor molecules was altered by common physiological events associated with GPCRs, including G protein binding, and receptor accumulation in clathrin-coated pits. We also confirmed that agonist also decreased the average diffusion coefficient for class A and B GPCRs, demonstrating that this parameter is a good index for estimating ligand effects on many GPCRs regardless of their phylogenetic groups, the chemical properties of the ligands, or G protein–coupling selectivity.


2013 ◽  
Vol 104 (2) ◽  
pp. 525a ◽  
Author(s):  
Laura Weimann ◽  
Steven F. Lee ◽  
James H. Felce ◽  
Simon J. Davis ◽  
David Klenerman

Nephron ◽  
2021 ◽  
pp. 1-4
Author(s):  
Nathan A. Zaidman ◽  
Jennifer L. Pluznick

G protein-coupled receptors (GPCRs) are cell surface proteins which play a key role in allowing cells, tissues, and organs to respond to changes in the external environment in order to maintain homeostasis. Despite the fact that GPCRs are known to play key roles in a variety of tissues, there are a large subset of GPCRs that remain poorly studied. In this minireview, we will summarize what is known regarding the “understudied” GPCRs with respect to renal function, and in so doing will highlight the promise represented by studying this gene family.


2000 ◽  
Vol 113 (13) ◽  
pp. 2463-2470 ◽  
Author(s):  
F. Santini ◽  
R.B. Penn ◽  
A.W. Gagnon ◽  
J.L. Benovic ◽  
J.H. Keen

Non-visual arrestins (arrestin-2 and arrestin-3) play critical roles in the desensitization and internalization of many G protein-coupled receptors. In vitro experiments have shown that both non-visual arrestins bind with high and approximately comparable affinities to activated, phosphorylated forms of receptors. They also exhibit high affinity binding, again of comparable magnitude, to clathrin. Further, agonist-promoted internalization of many receptors has been found to be stimulated by exogenous over-expression of either arrestin2 or arrestin3. The existence of multiple arrestins raises the question whether stimulated receptors are selective for a specific endogenous arrestin under more physiological conditions. Here we address this question in RBL-2H3 cells, a cell line that expresses comparable levels of endogenous arrestin-2 and arrestin-3. When (beta)(2)-adrenergic receptors are stably expressed in these cells the receptors internalize efficiently following agonist stimulation. However, by immunofluorescence microscopy we determine that only arrestin-3, but not arrestin-2, is rapidly recruited to clathrin coated pits upon receptor stimulation. Similarly, in RBL-2H3 cells that stably express physiological levels of m1AChR, the addition of carbachol selectively induces the localization of arrestin-3, but not arrestin-2, to coated pits. Thus, this work demonstrates coupling of G protein-coupled receptors to a specific non-visual arrestin in an in vivo setting.


2018 ◽  
Vol 217 (8) ◽  
pp. 2831-2849 ◽  
Author(s):  
Sungsu Lee ◽  
Han Yen Tan ◽  
Ivayla I. Geneva ◽  
Aleksandr Kruglov ◽  
Peter D. Calvert

Physical properties of primary cilia membranes in living cells were examined using two independent, high-spatiotemporal-resolution approaches: fast tracking of single quantum dot–labeled G protein–coupled receptors and a novel two-photon super-resolution fluorescence recovery after photobleaching of protein ensemble. Both approaches demonstrated the cilium membrane to be partitioned into corralled domains spanning 274 ± 20 nm, within which the receptors are transiently confined for 0.71 ± 0.09 s. The mean membrane diffusion coefficient within the corrals, Dm1 = 2.9 ± 0.41 µm2/s, showed that the ciliary membranes were among the most fluid encountered. At longer times, the apparent membrane diffusion coefficient, Dm2 = 0.23 ± 0.05 µm2/s, showed that corral boundaries impeded receptor diffusion 13-fold. Mathematical simulations predict the probability of G protein–coupled receptors crossing corral boundaries to be 1 in 472. Remarkably, latrunculin A, cytochalasin D, and jasplakinolide treatments altered the corral permeability. Ciliary membranes are thus partitioned into highly fluid membrane nanodomains that are delimited by filamentous actin.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Abdullah O. Khan ◽  
Carl W. White ◽  
Jeremy A. Pike ◽  
Jack Yule ◽  
Alexandre Slater ◽  
...  

Abstract The use of CRISPR-Cas9 genome editing to introduce endogenously expressed tags has the potential to address a number of the classical limitations of single molecule localisation microscopy. In this work we present the first systematic comparison of inserts introduced through CRISPR-knock in, with the aim of optimising this approach for single molecule imaging. We show that more highly monomeric and codon optimised variants of mEos result in improved expression at the TubA1B locus, despite the use of identical guides, homology templates, and selection strategies. We apply this approach to target the G protein-coupled receptor (GPCR) CXCR4 and show a further insert dependent effect on expression and protein function. Finally, we show that compared to over-expressed CXCR4, endogenously labelled samples allow for accurate single molecule quantification on ligand treatment. This suggests that despite the complications evident in CRISPR mediated labelling, the development of CRISPR-PALM has substantial quantitative benefits.


2010 ◽  
Vol 333 (1) ◽  
pp. 174-183 ◽  
Author(s):  
Chunmin Dong ◽  
Xiaoping Zhang ◽  
Fuguo Zhou ◽  
Huijuan Dou ◽  
Matthew T. Duvernay ◽  
...  

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