scholarly journals Organized cannabinoid receptor distribution in neurons revealed by super-resolution fluorescence imaging

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Hui Li ◽  
Jie Yang ◽  
Cuiping Tian ◽  
Min Diao ◽  
Quan Wang ◽  
...  
Keyword(s):  
G Protein ◽  
Fluorescence Imaging ◽  
Cannabinoid Receptor ◽  
Super Resolution ◽  
G Protein Coupled Receptors ◽  
Cellular Functions ◽  
Cannabinoid Receptor 1 ◽  
Intracellular Organization ◽  
Dynamic Movement ◽  
G Protein Coupled

Abstract G-protein-coupled receptors (GPCRs) play important roles in cellular functions. However, their intracellular organization is largely unknown. Through investigation of the cannabinoid receptor 1 (CB1), we discovered periodically repeating clusters of CB1 hotspots within the axons of neurons. We observed these CB1 hotspots interact with the membrane-associated periodic skeleton (MPS) forming a complex crucial in the regulation of CB1 signaling. Furthermore, we found that CB1 hotspot periodicity increased upon CB1 agonist application, and these activated CB1 displayed less dynamic movement compared to non-activated CB1. Our results suggest that CB1 forms periodic hotspots organized by the MPS as a mechanism to increase signaling efficacy upon activation.

scholarly journals Organized cannabinoid receptor distribution in neurons revealed by super-resolution fluorescence imaging

2020 ◽  
Author(s):  
Hui Li ◽  
Jie Yang ◽  
Tian Cuiping ◽  
Min Diao ◽  
Quan Wang ◽  
...  
Keyword(s):  
G Protein ◽  
Fluorescence Imaging ◽  
Cannabinoid Receptor ◽  
Super Resolution ◽  
G Protein Coupled Receptors ◽  
Cellular Functions ◽  
Cannabinoid Receptor 1 ◽  
Intracellular Organization ◽  
Dynamic Movement ◽  
G Protein Coupled

AbstractG-protein-coupled receptors (GPCRs) play important roles in cellular functions. However, their intracellular organization is largely unknown. Through investigation of the cannabinoid receptor 1 (CB1), we discovered periodically repeating clusters of CB1 hotspots within the axons of neurons. We observed these CB1 hotspots interact with the membrane-associated periodic skeleton (MPS) forming a complex crucial in the regulation of CB1 signaling. Furthermore, we found that CB1 hotspot periodicity increased upon CB1 agonist application, and these activated CB1 displayed less dynamic movement compared to non-activated CB1. Our results suggest that CB1 forms periodic hotspots organized by the MPS as a mechanism to increase signaling efficacy when being activated.

scholarly journals G protein-coupled receptor GPR55 promotes colorectal cancer and has opposing effects to cannabinoid receptor 1

2017 ◽  
Vol 142 (1) ◽  
pp. 121-132 ◽  
Author(s):  
Carina Hasenoehrl ◽  
David Feuersinger ◽  
Eva M Sturm ◽  
Thomas Bärnthaler ◽  
Ellen Heitzer ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
G Protein ◽  
Cannabinoid Receptor ◽  
G Protein Coupled Receptor ◽  
Cannabinoid Receptor 1 ◽  
Opposing Effects ◽  
G Protein Coupled

scholarly journals Actin filaments partition primary cilia membranes into distinct fluid corrals

2018 ◽  
Vol 217 (8) ◽  
pp. 2831-2849 ◽  
Author(s):  
Sungsu Lee ◽  
Han Yen Tan ◽  
Ivayla I. Geneva ◽  
Aleksandr Kruglov ◽  
Peter D. Calvert
Keyword(s):  
Diffusion Coefficient ◽  
G Protein ◽  
Primary Cilia ◽  
Super Resolution ◽  
G Protein Coupled Receptors ◽  
Membrane Diffusion ◽  
Filamentous Actin ◽  
Spatiotemporal Resolution ◽  
Fast Tracking ◽  
G Protein Coupled

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.

scholarly journals Identification of the C3a Receptor (C3AR1) as the Target of the VGF-derived Peptide TLQP-21 in Rodent Cells

2013 ◽  
Vol 288 (38) ◽  
pp. 27434-27443 ◽  
Author(s):  
Sebastien Hannedouche ◽  
Valerie Beck ◽  
Juliet Leighton-Davies ◽  
Martin Beibel ◽  
Guglielmo Roma ◽  
...  
Keyword(s):  
G Protein ◽  
Cellular Response ◽  
G Protein Coupled Receptors ◽  
Proteolytic Processing ◽  
Rodent Models ◽  
Cellular Functions ◽  
Genome Wide ◽  
Response To Stress ◽  
G Protein Coupled ◽  
Human Receptor

TLQP-21, a peptide derived from VGF (non-acronymic) by proteolytic processing, has been shown to modulate energy metabolism, differentiation, and cellular response to stress. Although extensively investigated, the receptor for this endogenous peptide has not previously been described. This study describes the use of a series of studies that show G protein-coupled receptor-mediated biological activity of TLQP-21 signaling in CHO-K1 cells. Unbiased genome-wide sequencing of the transcriptome from responsive CHO-K1 cells identified a prioritized list of possible G protein-coupled receptors bringing about this activity. Further experiments using a series of defined receptor antagonists and siRNAs led to the identification of complement C3a receptor-1 (C3AR1) as a target for TLQP-21 in rodents. We have not been able to demonstrate so far that this finding is translatable to the human receptor. Our results are in line with a large number of physiological observations in rodent models of food intake and metabolic control, where TLQP-21 shows activity. In addition, the sensitivity of TLQP-21 signaling to pertussis toxin is consistent with the known signaling pathway of C3AR1. The binding of TLQP-21 to C3AR1 not only has effects on signaling but also modulates cellular functions, as TLQP-21 was shown to have a role in directing migration of mouse RAW264.7 cells.

ADAMs as mediators of EGF receptor transactivation by G protein-coupled receptors

2006 ◽  
Vol 291 (1) ◽  
pp. C1-C10 ◽  
Author(s):  
Haruhiko Ohtsu ◽  
Peter J. Dempsey ◽  
Satoru Eguchi
Keyword(s):  
G Protein ◽  
Egf Receptor ◽  
Current Knowledge ◽  
G Protein Coupled Receptors ◽  
Surface Proteins ◽  
Egf Receptors ◽  
Cellular Functions ◽  
Egfr Transactivation ◽  
And Migration ◽  
G Protein Coupled

A disintegrin and metalloprotease (ADAM) is a membrane-anchored metalloprotease implicated in the ectodomain shedding of cell surface proteins, including the ligands for epidermal growth factor (EGF) receptors (EGFR)/ErbB. It has been well documented that the transactivation of the EGFR plays critical roles for many cellular functions, such as proliferation and migration mediated through multiple G protein-coupled receptors (GPCRs). Recent accumulating evidence has suggested that ADAMs are the key metalloproteases activated by several GPCR agonists to produce a mature EGFR ligand leading to the EGFR transactivation. In this review, we describe the current knowledge on ADAMs implicated in mediating EGFR transactivation. The major focus of the review will be on the possible upstream mechanisms of ADAM activation by GPCRs as well as downstream signal transduction and the pathophysiological significances of ADAM-dependent EGFR transactivation.

scholarly journals Cholesterol as a modulator of cannabinoid receptor CB2 signaling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexei Yeliseev ◽  
Malliga R. Iyer ◽  
Thomas T. Joseph ◽  
Nathan J. Coffey ◽  
Resat Cinar ◽  
...  
Keyword(s):  
G Protein ◽  
Md Simulation ◽  
Cannabinoid Receptor ◽  
Partial Agonist ◽  
G Protein Coupled Receptors ◽  
Affinity Ligands ◽  
Drug Candidates ◽  
Different Types ◽  
G Protein Coupled ◽  
Specific Ligand

AbstractSignaling through integral membrane G protein-coupled receptors (GPCRs) is influenced by lipid composition of cell membranes. By using novel high affinity ligands of human cannabinoid receptor CB2, we demonstrate that cholesterol increases basal activation levels of the receptor and alters the pharmacological categorization of these ligands. Our results revealed that (2-(6-chloro-2-((2,2,3,3-tetramethylcyclopropane-1-carbonyl)imino)benzo[d]thiazol-3(2H)-yl)ethyl acetate ligand (MRI-2646) acts as a partial agonist of CB2 in membranes devoid of cholesterol and as a neutral antagonist or a partial inverse agonist in cholesterol-containing membranes. The differential effects of a specific ligand on activation of CB2 in different types of membranes may have implications for screening of drug candidates in a search of modulators of GPCR activity. MD simulation suggests that cholesterol exerts an allosteric effect on the intracellular regions of the receptor that interact with the G-protein complex thereby altering the recruitment of G protein.

Pharmacological Characterization of Receptor Redistribution and β-Arrestin Recruitment Assays for the Cannabinoid Receptor 1

2009 ◽  
Vol 14 (7) ◽  
pp. 811-823 ◽  
Author(s):  
Miranda M.C. van der Lee ◽  
Marion Blomenröhr ◽  
Antoon A. van der Doelen ◽  
Jesse W.Y. Wat ◽  
Niels Smits ◽  
...  
Keyword(s):  
G Protein ◽  
Cannabinoid Receptor ◽  
Receptor Activation ◽  
Binding Affinities ◽  
Cannabinoid Receptor 1 ◽  
Pharmacological Characterization ◽  
Cellular Effects ◽  
Partial Agonists ◽  
C Terminus ◽  
G Protein Coupled

Receptor redistribution and β-arrestin recruitment assays provide a G-protein-subtype-independent method to measure ligand-stimulated activation of G-protein-coupled receptors. In particular β-arrestin assays are becoming an increasingly popular tool for drug discovery. The authors have compared a high-content-imaging-based Redistribution® assay and 2 nonimaging-based β-arrestin recruitment assays, Tango™ and PathHunter ™, for the cannabinoid receptor 1. Inasmuch as all 3 assays use receptors that are modified at the C-terminus, the authors verified their pharmacology via detection of Gαi coupling of the receptor in cAMP assays using reference ligands. The potencies and efficacies of the cannabinoid receptor agonists CP55,940 and WIN55,212-2 correlated well between the 3 assays, and are comparable with the measured ligand binding affinities. The inverse agonist SR141716 decreased basal signal in all 3 assays, but only in the Tango bla assay a reliable EC50 could be determined for this compound, suggesting that Tango is the most suitable assay for the identification of new inverse agonists. Both the Redistribution and the PathHunter assay could discriminate partial agonists from full agonists, whereas in the Tango assay partial agonists behaved as full agonists. Only the PathHunter cells allowed detection of cannabinoid receptor activation via β-arrestin recruitment and Gαi-protein-mediated inhibition of cAMP, thus enabling the identification of biased ligands that differ in these cellular effects. The characteristics and limitations of the different assays are discussed. ( Journal of Biomolecular Screening 2009:811-823)

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