scholarly journals GPCR desensitization: Acute and prolonged phases

2018 ◽  
Vol 41 ◽  
pp. 9-16 ◽  
Author(s):  
Sudarshan Rajagopal ◽  
Sudha K. Shenoy
Keyword(s):  
Gpcr Desensitization

scholarly journals The G Protein-Coupled Receptor Kinases (GRKs) in Chemokine Receptor-Mediated Immune Cell Migration: From Molecular Cues to Physiopathology

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 75
Author(s):  
Marta Laganà ◽  
Géraldine Schlecht-Louf ◽  
Françoise Bachelerie
Keyword(s):  
G Protein ◽  
Chemokine Receptor ◽  
Immune Cell ◽  
Neutrophil Migration ◽  
G Protein Coupled Receptor ◽  
Receptor Kinases ◽  
Immune Cell Migration ◽  
And Migration ◽  
G Protein Coupled ◽  
Gpcr Desensitization

Although G protein-coupled receptor kinases (GRKs) have long been known to regulate G protein-coupled receptor (GPCR) desensitization, their more recently characterized functions as scaffolds and signalling adapters underscore that this small family of proteins governs a larger array of physiological functions than originally suspected. This review explores how GRKs contribute to the complex signalling networks involved in the migration of immune cells along chemokine gradients sensed by cell surface GPCRs. We outline emerging evidence indicating that the coordinated docking of several GRKs on an active chemokine receptor determines a specific receptor phosphorylation barcode that will translate into distinct signalling and migration outcomes. The guidance cues for neutrophil migration are emphasized based on several alterations affecting GRKs or GPCRs reported to be involved in pathological conditions.

Abstract 013: Role for β-Arrestins in Stem/Precursor Cell Function and Cardiac Regeneration

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Anna M Gumpert ◽  
Mai Chen ◽  
Henriette Brinks ◽  
Jang-Whan Bae ◽  
Karsten Peppel ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Cell Death ◽  
Cell Function ◽  
Ischemic Injury ◽  
Precursor Cells ◽  
Cardiac Repair ◽  
Precursor Cell ◽  
Gpcr Desensitization

Chronic heart failure after myocardial injury (MI) is characterized by an extensive loss of myocytes due to considerable cell death. Bone marrow derived stem cells (BMSCs) can transdifferentiate and show potential for regenerating the myocardium after MI. Stem cell mobilization, egress from the bone marrow and recruitment to the site of injury can be regulated by signals through G protein coupled receptors (GPCRs). βArrestins have signalling and scaffolding functions and act as downstream regulators of GPCR desensitization and endocytosis. We explored the potential role for βArrestins in cardiac precursor cell function, concentrating on BMSCs. Using knockout (KO) mice, we investigated the role βArrestin1 (βArr1) and βArrestin2 (βArr2), their modulation of regenerative competence of BMSCs and their contribution to cardiac repair after ischemic injury. in vitro, we observed that BM derived cells devoid of either βArr1 or βArr2 are slower to proliferate, colonize and migrate, compared to wild type (WT) BM cells. We also observed elevated cell death in βArr2 deficient cells following oxidative stress. Additionally, the number of cKit+ stem cells, thought to be potential cardiac precursor cells, was significantly lower in the BM and blood of βArr KO vs WT. Similarly, BM and blood of the chimeras contained fewer and less viable cardiac stem/precursor cells pre and post MI, compared to WT transplanted controls. In our in vivo study, we carried out BM transplants to determine whether the βArrs may be involved in cardiac repair. WT mice were irradiated and received BM transplants from WT, βArr1 KO or βArr2 KO mice. Following BM reconstitution, mice underwent MI and their recovery was monitored. Interestingly, chimeric mice with βArr1 and βArr2 KO BM had significantly inferior outcomes, including significantly decreased post MI survival with βArr2 KO BM and both βArr chimeras had significantly lower cardiac function post MI than mice receiving WT BM. Histology revealed that both chimeras developed larger infarcts and hypertrophy at an faster rate. We conclude that βArrs play a novel role downstream of GPCR desensitization in cardiac progenitor cells in BM and appear to be critically involved in the heart’s response to ischemic injury via cardiac repair and regeneration.

scholarly journals Role of GRK6 in the Regulation of Platelet Activation through Selective G Protein-Coupled Receptor (GPCR) Desensitization

2020 ◽  
Vol 21 (11) ◽  
pp. 3932 ◽  
Author(s):  
Preeti Kumari Chaudhary ◽  
Sanggu Kim ◽  
Youngheun Jee ◽  
Seung-Hun Lee ◽  
Kyung-Mee Park ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
G Protein ◽  
Platelet Activation ◽  
Functional Role ◽  
Thrombus Formation ◽  
Receptor Activation ◽  
G Protein Coupled ◽  
Gpcr Desensitization ◽  
Stimulation Of

Platelet G protein-coupled receptors (GPCRs) regulate platelet function by mediating the response to various agonists, including adenosine diphosphate (ADP), thromboxane A2, and thrombin. Although GPCR kinases (GRKs) are considered to have the crucial roles in most GPCR functions, little is known regarding the regulation of GPCR signaling and mechanisms of GPCR desensitization by GRKs in platelets. In this study, we investigated the functional role of GRK6 and the molecular basis for regulation of specific GPCR desensitization by GRK6 in platelets. We used GRK6 knockout mice to evaluate the functional role of GRK6 in platelet activation. Platelet aggregation, dense- and α-granule secretion, and fibrinogen receptor activation induced by 2-MeSADP, U46619, thrombin, and AYPGKF were significantly potentiated in GRK6−/− platelets compared to the wild-type (WT) platelets. However, collagen-related peptide (CRP)-induced platelet aggregation and secretion were not affected in GRK6−/− platelets. Interestingly, platelet aggregation induced by co-stimulation of serotonin and epinephrine which activate Gq-coupled 5HT2A and Gz-coupled α2A adrenergic receptors, respectively, was not affected in GRK6−/− platelets, suggesting that GRK6 was involved in specific GPCR regulation. In addition, platelet aggregation in response to the second challenge of ADP and AYPGKF was restored in GRK6−/− platelets whereas re-stimulation of the agonist failed to induce aggregation in WT platelets, indicating that GRK6 contributed to P2Y1, P2Y12, and PAR4 receptor desensitization. Furthermore, 2-MeSADP-induced Akt phosphorylation and AYPGKF-induced Akt, extracellular signal-related kinase (ERK), and protein kinase Cδ (PKCδ) phosphorylation were significantly potentiated in GRK6−/− platelets. Finally, GRK6−/− mice exhibited an enhanced and stable thrombus formation after FeCl3 injury to the carotid artery and shorter tail bleeding times, indicating that GRK6−/− mice were more susceptible to thrombosis and hemostasis. We conclude that GRK6 plays an important role in regulating platelet functional responses and thrombus formation through selective GPCR desensitization.

Self-Checking Cell-Based Assays for GPCR Desensitization and Resensitization

2014 ◽  
Vol 19 (8) ◽  
pp. 1220-1226 ◽  
Author(s):  
Gregory W. Fisher ◽  
Margaret H. Fuhrman ◽  
Sally A. Adler ◽  
Christopher Szent-Gyorgyi ◽  
Alan S. Waggoner ◽  
...  
Keyword(s):  
Prescription Drugs ◽  
Cell Biology ◽  
Organic Molecules ◽  
G Protein Coupled Receptors ◽  
Receptor Desensitization ◽  
Endogenous Ligand ◽  
Target Class ◽  
Cell Assays ◽  
G Protein Coupled ◽  
Gpcr Desensitization

G protein–coupled receptors (GPCRs) play stimulatory or modulatory roles in numerous physiological states and processes, including growth and development, vision, taste and olfaction, behavior and learning, emotion and mood, inflammation, and autonomic functions such as blood pressure, heart rate, and digestion. GPCRs constitute the largest protein superfamily in the human and are the largest target class for prescription drugs, yet most are poorly characterized, and of the more than 350 nonolfactory human GPCRs, over 100 are orphans for which no endogenous ligand has yet been convincingly identified. We here describe new live-cell assays that use recombinant GPCRs to quantify two general features of GPCR cell biology—receptor desensitization and resensitization. The assays employ a fluorogen-activating protein (FAP) reporter that reversibly complexes with either of two soluble organic molecules (fluorogens) whose fluorescence is strongly enhanced when complexed with the FAP. Both assays require no wash or cleanup steps and are readily performed in microwell plates, making them adaptable to high-throughput drug discovery applications.

scholarly journals Agonist-selective mechanisms of GPCR desensitization

2008 ◽  
Vol 153 (S1) ◽  
pp. S379-S388 ◽  
Author(s):  
E Kelly ◽  
C P Bailey ◽  
G Henderson
Keyword(s):  
Gpcr Desensitization

Abstract P006: A Potential Role for β-Arrestins in Cardiac Regeneration

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Anna M Gumpert ◽  
Mai Chen ◽  
Henriette Brinks ◽  
Karsten Peppel ◽  
Erhe Gao ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Myocardial Injury ◽  
Cell Function ◽  
Cardiac Regeneration ◽  
Cardiac Repair ◽  
Cell Mobilization ◽  
Apoptosis And Necrosis ◽  
G Protein Coupled ◽  
Gpcr Desensitization

Development of chronic heart failure (HF) syndrome following myocardial injury (MI) is characterized by an extensive loss of myocytes due to substantial apoptosis and necrosis. As bone marrow derived stem cells (BMSCs) are capable of transdifferentiating, they also show potential for regenerating the myocardium after infarction. Stem cell mobilization, egress from the bone marrow and homing to the site of injury can be regulated by signals through G protein-coupled receptors (GPCRs). β-arrestins are known for their signalling and scaffolding functions and as downstream regulators of GPCR desensitization and endocytosis in particular. We have begun to investigate whether β-arrestins play any role in cardiac precursor cell function concentrating on the properties of BMSCs. Using knockout (KO) mice, we investigated the role β-arrestin1 (βArr1) and β-arrestin2 (βArr2) with respect to modulation of regenerative competence of BMSCs and their contribution to cardiac repair following ischemic injury. First, BM-derived cells devoid of either βArr1 or βArr2 were found to proliferate and colonize in a significantly deficient manner compared to BM cells isolated from wild-type (WT) mice. In addition, the number of c-kit positive cardiac stem cells (as a % of total BM) were significantly lower in the βArr KO mice compared to WT. We carried out BM transplant studies to begin to determine whether the βArrs may play a role in cardiac repair. In our study, WT mice were irradiated and then received BM transplants from either WT donors as a control or BM from βArr1 or βArr2 KO mice. Subsequent to BM reconstitution, mice underwent a myocardial infarction (MI) and their condition was followed. Interestingly, chimeric mice with βArr1 and βArr2 KO BM had significantly poorer outcomes than mice receiving WT BM. This included significantly decreased post-MI survival with βArr2 KO BM and both βArr chimeras had significantly lower cardiac function post-MI compared to mice receiving WT BM. Additionally, our analyses of the BM cells and very small embryonic-like stem cells (VSELs) circulating in peripheral blood (PB), indicate that βArr-KO BM and PB contain fewer and less viable cardiac stem/precursor cells compared to WT transplanted controls.

Beta-arrestin and GPCR desensitization, internalization, and signaling

2001 ◽  
Vol 29 (3) ◽  
pp. A64-A64
Author(s):  
S. A. Laporte ◽  
M. G. Caron
Keyword(s):  
Gpcr Desensitization
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