scholarly journals Authentic and Ectopically Expressed MRGPRX2 Elicit Similar Mechanisms to Stimulate Degranulation of Mast Cells

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 376
Author(s):  
Pia Lazki-Hagenbach ◽  
Hydar Ali ◽  
Ronit Sagi-Eisenberg
Keyword(s):  
Mast Cells ◽  
Substance P ◽  
G Protein ◽  
Map Kinases ◽  
G Protein Coupled Receptors ◽  
Adequate Model ◽  
Similar Dose ◽  
Wide Range ◽  
Underlying Mechanisms ◽  
G Protein Coupled

The identification of the Mas-related G-protein-coupled receptors (Mrgpr) as targets of diverse stimuli of mast cells (MCs), including neuropeptides and pseudo-allergy causing drugs, has placed these receptors at a prime position in MC research. However, the species-dependent diversity of these receptors raises the need for an adequate model for investigating the human MRGPRX2 receptor. RBL-2H3 cells, stably transfected with MRGPRX2 (RBL-MRGPRX2), are increasingly used for this purpose. Therefore, we investigated whether ectopically expressed MRGPRX2, in rat MCs, recapitulates its authentic signaling. To this purpose, we performed a broad comparative study of the responses of human LAD-2 MCs that express MRGPRX2 endogenously, and RBL-MRGPRX2 cells to compound 48/80, substance P and vancomycin, three proto-type ligands of MRGPRX2. We demonstrate that both models share similar dose–response relationships, kinetics and sensitivities to a wide range of signaling targeting drugs. Therefore, our results indicate that ectopically expressed MRGPRX2 preserves the signaling pathways employed to evoke human MC degranulation, which we show to rely on ERK1/2 MAP kinases, phospholipase C (PLC) and autophagy-related signaling. Importantly, we also show that the underlying mechanisms of MRGPRX2-triggered MC degranulation in either LAD-2 or RBL-MRGPRX2 cells are different from those elicited by its rodent orthologs.

scholarly journals Mini-review: antibody therapeutics targeting G protein-coupled receptors and ion channels

2020 ◽  
Vol 3 (4) ◽  
pp. 257-264
Author(s):  
Catherine J Hutchings
Keyword(s):  
Ion Channels ◽  
Research And Development ◽  
Small Molecules ◽  
G Protein ◽  
Clinical Studies ◽  
G Protein Coupled Receptors ◽  
Protein Targets ◽  
Antibody Therapeutics ◽  
Wide Range ◽  
G Protein Coupled

Abstract Antibodies are now well established as therapeutics with many additional advantages over small molecules and peptides relative to their selectivity, bioavailability, half-life and effector function. Major classes of membrane-associated protein targets include G protein-coupled receptors (GPCRs) and ion channels that are linked to a wide range of disease indications across all therapeutic areas. This mini-review summarizes the antibody target landscape for both GPCRs and ion channels as well as current progress in the respective research and development pipelines with some example case studies highlighted from clinical studies, including those being evaluated for the treatment of symptoms in COVID-19 infection.

scholarly journals Assembly of G Protein-Coupled Receptors onto Nanosized Bacterial Magnetic Particles Using Mms16 as an Anchor Molecule

2004 ◽  
Vol 70 (5) ◽  
pp. 2880-2885 ◽  
Author(s):  
Tomoko Yoshino ◽  
Masayoshi Takahashi ◽  
Haruko Takeyama ◽  
Yoshiko Okamura ◽  
Fukuichi Kato ◽  
...  
Keyword(s):  
G Protein ◽  
Magnetic Particles ◽  
Lipid Membrane ◽  
Specific Protein ◽  
G Protein Coupled Receptors ◽  
Native Conformation ◽  
Wide Range ◽  
Bacterial Magnetic Particles ◽  
Magnetospirillum Magneticum ◽  
G Protein Coupled

ABSTRACT G protein-coupled receptors (GPCRs) play a central role in a wide range of biological processes and are prime targets for drug discovery. GPCRs have large hydrophobic domains, and therefore purification of GPCRs from cells is frequently time-consuming and typically results in loss of native conformation. In this work, GPCRs have been successfully assembled into the lipid membrane of nanosized bacterial magnetic particles (BMPs) produced by the magnetic bacterium Magnetospirillum magneticum AMB-1. A BMP-specific protein, Mms16, was used as an anchor molecule, and localization of heterologous Mms16 on BMPs was confirmed by luciferase fusion studies. Stable luminescence was obtained from BMPs bearing Mms16 fused with luciferase at the C-terminal region. D1 dopamine receptor (D1R), a GPCR, was also efficiently assembled onto BMPs by using Mms16 as an anchor molecule. D1R-BMP complexes were simply extracted by magnetic separation from ruptured AMB-1 transformants. After washing, the complexes were ready to use for analysis. This system conveniently refines the native conformation of GPCRs without the need for detergent solubilization, purification, and reconstitution after cell disruption.

scholarly journals 'Location, location, location': activation and targeting of MAP kinases by G protein-coupled receptors

2003 ◽  
Vol 30 (2) ◽  
pp. 117-126 ◽  
Author(s):  
LM Luttrell
Keyword(s):  
Map Kinase ◽  
G Protein ◽  
Tyrosine Kinases ◽  
Map Kinases ◽  
Focal Adhesions ◽  
G Protein Coupled Receptors ◽  
Cellular Growth ◽  
Substantial Impact ◽  
Kinase Activation ◽  
G Protein Coupled

A growing body of data supports the conclusion that G protein-coupled receptors can regulate cellular growth and differentiation by controlling the activity of MAP kinases. The activation of heterotrimeric G protein pools initiates a complex network of signals leading to MAP kinase activation that frequently involves cross-talk between G protein-coupled receptors and receptor tyrosine kinases or focal adhesions. The dominant mechanism of MAP kinase activation varies significantly between receptor and cell type. Moreover, the mechanism of MAP kinase activation has a substantial impact on MAP kinase function. Some signals lead to the targeting of activated MAP kinase to specific extranuclear locations, while others activate a MAP kinase pool that is free to translocate to the nucleus and contribute to a mitogenic response.

scholarly journals Methods used to study the oligomeric structure of G-protein-coupled receptors

2017 ◽  
Vol 37 (2) ◽  
Author(s):  
Hui Guo ◽  
Su An ◽  
Richard Ward ◽  
Yang Yang ◽  
Ying Liu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
G Protein ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
G Protein Coupled Receptors ◽  
Experimental Techniques ◽  
Distribution Analysis ◽  
Wide Range ◽  
And Function ◽  
G Protein Coupled

G-protein-coupled receptors (GPCRs), which constitute the largest family of cell surface receptors, were originally thought to function as monomers, but are now recognized as being able to act in a wide range of oligomeric states and indeed, it is known that the oligomerization state of a GPCR can modulate its pharmacology and function. A number of experimental techniques have been devised to study GPCR oligomerization including those based upon traditional biochemistry such as blue-native PAGE (BN-PAGE), co-immunoprecipitation (Co-IP) and protein-fragment complementation assays (PCAs), those based upon resonance energy transfer, FRET, time-resolved FRET (TR-FRET), FRET spectrometry and bioluminescence resonance energy transfer (BRET). Those based upon microscopy such as FRAP, total internal reflection fluorescence microscopy (TIRFM), spatial intensity distribution analysis (SpIDA) and various single molecule imaging techniques. Finally with the solution of a growing number of crystal structures, X-ray crystallography must be acknowledged as an important source of discovery in this field. A different, but in many ways complementary approach to the use of more traditional experimental techniques, are those involving computational methods that possess obvious merit in the study of the dynamics of oligomer formation and function. Here, we summarize the latest developments that have been made in the methods used to study GPCR oligomerization and give an overview of their application.

scholarly journals Targeting islet G-protein-coupled receptors for type 2 diabetes therapy

2021 ◽  
Author(s):  
Shanta J. Persaud ◽  
Oladapo E. Olaniru ◽  
Patricio Atanes
Keyword(s):  
Type 2 Diabetes ◽  
G Protein ◽  
G Protein Coupled Receptors ◽  
Pharmaceutical Companies ◽  
Β Cells ◽  
Diabetes Therapy ◽  
Wide Range ◽  
Mass Expansion ◽  
G Protein Coupled

The majority of people with diabetes have type 2 diabetes (T2D), where hyperglycaemia occurs because the islet β-cells are unable to secrete enough insulin, usually in the context of insulin resistance that arises because of fat mass expansion. There are a range of pharmacotherapies in current use to treat T2D and pharmaceutical companies are actively engaged in the development of novel therapies for better glucose control. Ligands that target G-protein-coupled receptors (GPCRs) are obvious candidates because they are used successfully for a wide range of disorders and GLP-1 receptor agonists, which are a relatively recent class of diabetes therapy, have proved to be very effective in treating T2D. We provide here an overview of current successes, some drawbacks and future possibilities for GPCR-based T2D therapies.

scholarly journals G-protein-coupled receptors regulate autophagy by ZBTB16-mediated ubiquitination and proteasomal degradation of Atg14L

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Tao Zhang ◽  
Kangyun Dong ◽  
Wei Liang ◽  
Daichao Xu ◽  
Hongguang Xia ◽  
...  
Keyword(s):  
Mouse Model ◽  
Neurodegenerative Diseases ◽  
G Protein ◽  
Ubiquitin Ligase ◽  
E3 Ubiquitin Ligase ◽  
G Protein Coupled Receptors ◽  
Misfolded Proteins ◽  
Ubiquitin Ligase Complex ◽  
Wide Range ◽  
G Protein Coupled

Autophagy is an important intracellular catabolic mechanism involved in the removal of misfolded proteins. Atg14L, the mammalian ortholog of Atg14 in yeast and a critical regulator of autophagy, mediates the production PtdIns3P to initiate the formation of autophagosomes. However, it is not clear how Atg14L is regulated. In this study, we demonstrate that ubiquitination and degradation of Atg14L is controlled by ZBTB16-Cullin3-Roc1 E3 ubiquitin ligase complex. Furthermore, we show that a wide range of G-protein-coupled receptor (GPCR) ligands and agonists regulate the levels of Atg14L through ZBTB16. In addition, we show that the activation of autophagy by pharmacological inhibition of GPCR reduces the accumulation of misfolded proteins and protects against behavior dysfunction in a mouse model of Huntington's disease. Our study demonstrates a common molecular mechanism by which the activation of GPCRs leads to the suppression of autophagy and a pharmacological strategy to activate autophagy in the CNS for the treatment of neurodegenerative diseases.

scholarly journals Lipid nanoparticle technologies for the study of G protein-coupled receptors in lipid environments

2020 ◽  
Vol 12 (6) ◽  
pp. 1287-1302 ◽  
Author(s):  
Steven Lavington ◽  
Anthony Watts
Keyword(s):  
Membrane Proteins ◽  
G Protein ◽  
Drug Targets ◽  
Large Family ◽  
G Protein Coupled Receptors ◽  
Integral Membrane Proteins ◽  
Lipid Nanoparticle ◽  
Wide Range ◽  
Biophysical Studies ◽  
G Protein Coupled

AbstractG protein-coupled receptors (GPCRs) are a large family of integral membrane proteins which conduct a wide range of biological roles and represent significant drug targets. Most biophysical and structural studies of GPCRs have been conducted on detergent-solubilised receptors, and it is clear that detergents can have detrimental effects on GPCR function. Simultaneously, there is increasing appreciation of roles for specific lipids in modulation of GPCR function. Lipid nanoparticles such as nanodiscs and styrene maleic acid lipid particles (SMALPs) offer opportunities to study integral membrane proteins in lipid environments, in a form that is soluble and amenable to structural and biophysical experiments. Here, we review the application of lipid nanoparticle technologies to the study of GPCRs, assessing the relative merits and limitations of each system. We highlight how these technologies can provide superior platforms to detergents for structural and biophysical studies of GPCRs and inform on roles for protein-lipid interactions in GPCR function.

scholarly journals Candesartan abrogates G protein-coupled receptors agonist-induced MAPK activation and cardiac myocyte hypertrophy

2001 ◽  
Vol 2 (1_suppl) ◽  
pp. S154-S161 ◽  
Author(s):  
Djamel Lebeche ◽  
Zhao Bin Kang ◽  
Roger Hajjar
Keyword(s):  
Cardiac Hypertrophy ◽  
G Protein ◽  
Map Kinases ◽  
At1 Receptor ◽  
G Protein Coupled Receptors ◽  
Neonatal Rat ◽  
Leucine Incorporation ◽  
Dependent Manner ◽  
Ang Ii ◽  
G Protein Coupled

The renin-angiotensin-aldosterone system (RAAS) has been identified as a major contributor to the development of cardiac hypertrophy and the subsequent transition to heart failure. G protein-coupled receptors agonists such as angiotensin II (Ang II), endothelin-1 (ET-1) and phenylephrine (PE) have been implicated in hypertrophic responses in ventricular myocytes through the activation of several families of MAP kinases. In this study we examined the effect of candesartan, an Ang II type 1-(AT1)-receptor antagonist, on cardiac hypertrophy by using cultured neonatal rat cardiomyocytes. Stimulation with Ang II (100 nM), ET-1 (100 nM) or PE (1 µM) induced marked increases in [3H]Leucine incorporation (≥ 50%), compatible with enhanced protein synthesis. The addition of candesartan abrogated the increase in [3H]Leucine incorporation in response not only to Ang II but also to ET-1 and PE. To elucidate the mechanisms involved in this antihypertrophic effect of candesartan, we studied the activation of p38-MAPK, extracellular signal-regulated kinases (ERK1/2) and stress-activated protein kinases (SAPKs). Ang II, ET-1 and PE increased the phosphorylation levels of ERK1/2, p54 SAPK and p46SAPK and p38 in a time-dependent manner. This activation was completely blocked in the case of Ang II by pretreatment with candesartan. ET-1-induced activation of ERKs, SAPKs and p38 was also partially, but significantly, reduced by candesartan. PE-induced activation of SAPKs, but not ERKs and p38, was also reduced by candesartan. These results suggest that the hypertrophic response to ET-1 and PE, along with Ang II, is dependent upon a functioning AT1-receptor and may be mediated by AT 1 activation of the MAP kinases.

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