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  • Mechanism of enhanced sensitivity of mutated β-adrenergic-like octopamine receptor to amitraz in...

    October 2022 Mechanism of enhanced sensitivity of mutated β-adrenergic-like octopamine receptor to amitraz in honeybee Apis mellifera: An insight from MD simulations "Background: Amitraz is one of the critical acaricides/insecticides for effective control of pest infestation of Varroa destructor mite, a devastating parasite of Apis mellifera, because of its low toxicity to honeybees. Previous assays verified that a typical G protein-coupled receptor, β-adrenergic-like octopamine receptor (Octβ2R), is the unique target of amitraz, but the honeybee Octβ2R resists to amitraz. However, the underlying molecular mechanism of the enhanced sensitivity or toxicity of amitraz to mutated honeybee Octβ2RE208V/I335T/I350V is not fully understood. Here, molecular dynamics simulations are employed to explore the implied mechanism of the enhanced sensitivity to amitraz in mutant honeybee Octβ2R." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Focusing on the role of secretin/adhesion (Class B) G protein-coupled receptors in placental...

    October 2022 Focusing on the role of secretin/adhesion (Class B) G protein-coupled receptors in placental development and preeclampsia "Preeclampsia, a clinical syndrome mainly characterized by hypertension and proteinuria, with a worldwide incidence of 3–8% and high maternal mortality, is a risk factor highly associated with maternal and offspring cardiovascular disease. However, the etiology and pathogenesis of preeclampsia are complicated and have not been fully elucidated. Obesity, immunological diseases and endocrine metabolic diseases are high-risk factors for the development of preeclampsia. Effective methods to treat preeclampsia are lacking, and termination of pregnancy remains the only curative treatment for preeclampsia. The pathogenesis of preeclampsia include poor placentation, uteroplacental malperfusion, oxidative stress, endoplasmic reticulum stress, dysregulated immune tolerance, vascular inflammation and endothelial cell dysfunction. The notion that placenta is the core factor in the pathogenesis of preeclampsia is still prevailing. G protein-coupled receptors, the largest family of membrane proteins in eukaryotes and the largest drug target family to date, exhibit diversity in structure and function. Among them, the secretin/adhesion (Class B) G protein-coupled receptors are essential drug targets for human diseases, such as endocrine diseases and cardiometabolic diseases. Given the great value of the secretin/adhesion (Class B) G protein-coupled receptors in the regulation of cardiovascular system function and the drug target exploration, we summarize the role of these receptors in placental development and preeclampsia, and outlined the relevant pathological mechanisms, thereby providing potential drug targets for preeclampsia treatment." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Enhanced membrane binding of oncogenic G protein αqQ209L confers resistance to inhibitor YM-254890

    October 2022 "Heterotrimeric G proteins couple activated G protein-coupled receptors (GPCR) to intracellular signaling pathways. They can also function independently of GPCR activation upon acquiring mutations that prevent GTPase activity and result in constitutive signaling, as occurs with the αqQ209L mutation in uveal melanoma. YM-254890 (YM) can inhibit signaling by both GPCR-activated wild type αq and GPCR-independent αqQ209L. Although YM inhibits wild type αq by binding to αq-GDP and preventing GDP/GTP exchange, the mechanism of YM inhibition of cellular αqQ209L remains to be fully understood. Here, we show that YM promotes a subcellular redistribution of αqQ209L from the plasma membrane (PM) to the cytoplasm. To test if this loss of PM localization could contribute to the mechanism of inhibition of αqQ209L by YM, we developed and examined N-terminal mutants of αqQ209L, termed PM-restricted αqQ209L, in which the addition of membrane-binding motifs enhanced PM localization and prevented YM-promoted redistribution. Treatment of cells with YM failed to inhibit signaling by these PM-restricted αqQ209L. Additionally, pull-down experiments demonstrated that YM promotes similar conformational changes in both αqQ209L and PM-restricted αqQ209L, resulting in increased binding to βγ and decreased binding to regulator RGS2, and effectors p63RhoGEF-DH/PH and phospholipase C-β. GPCR-dependent signaling by PM-restricted wild type αq is strongly inhibited by YM, demonstrating that resistance to YM inhibition by membrane-binding mutants is specific to constitutively active αqQ209L. Together, these results indicate that changes in membrane binding impact the ability of YM to inhibit αqQ209L and suggest that YM contributes to inhibition of αqQ209L by promoting its relocalization." Read more at the source #DrGPCR #GPCR #IndustryNews

  • N-terminal alterations turn the gut hormone GLP-2 into an antagonist with gradual loss of GLP-2 ...

    October 2022 N-terminal alterations turn the gut hormone GLP-2 into an antagonist with gradual loss of GLP-2 receptor selectivity towards more GLP-1 receptor interaction "Background and purpose: To fully elucidate the regulatory role of the GLP-2 system in the gut and the bones, potent and selective GLP-2 receptor (GLP-2R) antagonists are needed. Searching for antagonist activity, we performed systematic N-terminal truncations of human GLP-2(1-33). Experimental approach: COS-7 cells were transfected with the human GLP-2R and assessed for cAMP accumulation or competition binding using 125 I-GLP-2(1-33)[M10Y]. To examine selectivity, COS-7 cells expressing human GLP-1 or GIP receptors were assessed for cAMP accumulation." Read more at the source #DrGPCR #GPCR #IndustryNews

  • GPR15 expressed in T lymphocytes from RA patients is involved in leukocyte chemotaxis to the...

    October 2022 GPR15 expressed in T lymphocytes from RA patients is involved in leukocyte chemotaxis to the synovium "The rheumatoid arthritis (RA) inflammatory process occurs in the joints where immune cells are attracted into the synovium to promote remodeling and tissue damage. GPR15 is a G protein-coupled receptor (GPCR) located on chromosome 3 and has similarity in its sequence with chemokine receptors. Recent evidence indicates that GPR15 may be associated with modulation of the chronic inflammatory response. We evaluated the expression of GPR15 and GPR15L in blood and synovial tissue samples from RA patients, as well as to perform a functional migration assay in response to GPR15L. The expression of GPR15 and c10orf99/gpr15l mRNA was analyzed by RT-qPCR. Samples of synovial fluid and peripheral blood were analyzed for CD45+CD3+CD4+GPR15+ and CD45+CD3+CD8+GPR15+ T cell frequency comparing RA patients versus control subjects by flow cytometry. Migration assays were performed using PBMCs isolated from these individuals in response to the synthetic GPR15 ligand. Statistical analysis included Kruskal-Wallis test, T-test, or Mann-Whitney U test, according to data distribution. A higher expression in the mRNA for GPR15 was identified in early RA subjects. The frequencies of CD4+/CD8+ GPR15+ T lymphocytes are higher in RA patients comparing with healthy subjects. Also, the frequency CD4+/CD8+ GPR15+ T lymphocytes are higher in synovial fluid of established RA patients comparing with OA patients. GPR15 and GPR15L are present in the synovial tissue of RA patients and GPR15L promotes migration of PBMCs from RA patients and healthy subjects. Our results suggest that GPR15/GPR15L have a pathogenic role in RA and their antagonizing could be a therapeutic approach in RA." Read more at the source #DrGPCR #GPCR #IndustryNews

  • PH-Binding Motif in PAR4 Oncogene: From Molecular Mechanism to Drug Design

    October 2022 "While the role of G-protein-coupled receptors (GPCR) in cancer is acknowledged, their underlying signaling pathways are understudied. Protease-activated receptors (PAR), a subgroup of GPCRs, form a family of four members (PAR1-4) centrally involved in epithelial malignancies. PAR4 emerges as a potent oncogene, capable of inducing tumor generation. Here, we demonstrate identification of a pleckstrin-homology (PH)-binding motif within PAR4, critical for colon cancer growth. In addition to PH-Akt/PKB association, other PH-containing signal proteins such as Gab1 and Sos1 also associate with PAR4. Point mutations are in the C-tail of PAR4 PH-binding domain; F347 L and D349A, but not E346A, abrogate these associations. Pc(4-4), a lead backbone cyclic peptide, was selected out of a mini-library, directed toward PAR2&4 PH-binding motifs. It effectively attenuates PAR2&4-Akt/PKB associations; PAR4 instigated Matrigel invasion and migration in vitro and tumor development in vivo. EGFR/erbB is among the most prominent cancer targets. AYPGKF peptide ligand activation of PAR4 induces EGF receptor (EGFR) Tyr-phosphorylation, effectively inhibited by Pc(4-4). The presence of PAR2 and PAR4 in biopsies of aggressive breast and colon cancer tissue specimens is demonstrated. We propose that Pc(4-4) may serve as a powerful drug not only toward PAR-expressing tumors but also for treating EGFR/erbB-expressing tumors in cases of resistance to traditional therapies. Overall, our studies are expected to allocate new targets for cancer therapy. Pc(4-4) may become a promising candidate for future therapeutic cancer treatment." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Single-molecule counting applied to the study of GPCR oligomerization

    October 2022 "Single-molecule counting techniques enable a precise determination of the intracellular abundance and stoichiometry of proteins and macromolecular complexes. These details are often challenging to quantitatively assess yet are essential for our understanding of cellular function. Consider G-protein-coupled receptors-an expansive class of transmembrane signaling proteins that participate in many vital physiological functions making them a popular target for drug development. While early evidence for the role of oligomerization in receptor signaling came from ensemble biochemical and biophysical assays, innovations in single-molecule measurements are now driving a paradigm shift in our understanding of its relevance. Here, we review recent developments in single-molecule counting with a focus on photobleaching step counting and the emerging technique of quantitative single-molecule localization microscopy-with a particular emphasis on the potential for these techniques to advance our understanding of the role of oligomerization in G-protein-coupled receptor signaling." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Membrane Lipids Are an Integral Part of Transmembrane Allosteric Sites in GPCRs: A Case Study of...

    October 2022 Membrane Lipids Are an Integral Part of Transmembrane Allosteric Sites in GPCRs: A Case Study of Cannabinoid CB1 Receptor Bound to a Negative Allosteric Modulator, ORG27569, and Analogs "A growing number of G-protein-coupled receptor (GPCR) structures reveal novel transmembrane lipid-exposed allosteric sites. Ligands must first partition into the surrounding membrane and take lipid paths to these sites. Remarkably, a significant part of the bound ligands appears exposed to the membrane lipids. The experimental structures do not usually account for the surrounding lipids, and their apparent contribution to ligand access and binding is often overlooked and poorly understood. Using classical and enhanced molecular dynamics simulations, we show that membrane lipids are critical in the access and binding of ORG27569 and its analogs at the transmembrane site of cannabinoid CB1 receptor. The observed differences in the binding affinity and cooperativity arise from the functional groups that interact primarily with lipids. Our results demonstrate the significance of incorporating membrane lipids as an integral component of transmembrane sites for accurate characterization, binding-affinity calculations, and lead optimization in drug discovery." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Dopamine activates astrocytes in prefrontal cortex via α1-adrenergic receptors

    October 2022 "The prefrontal cortex (PFC) is a hub for cognitive control, and dopamine profoundly influences its functions. In other brain regions, astrocytes sense diverse neurotransmitters and neuromodulators and, in turn, orchestrate regulation of neuroactive substances. However, basic physiology of PFC astrocytes, including which neuromodulatory signals they respond to and how they contribute to PFC function, is unclear. Here, we characterize divergent signaling signatures in mouse astrocytes of the PFC and primary sensory cortex, which show differential responsiveness to locomotion. We find that PFC astrocytes express receptors for dopamine but are unresponsive through the Gs/Gi-cAMP pathway. Instead, fast calcium signals in PFC astrocytes are time locked to dopamine release and are mediated by α1-adrenergic receptors both ex vivo and in vivo. Further, we describe dopamine-triggered regulation of extracellular ATP at PFC astrocyte territories. Thus, we identify astrocytes as active players in dopaminergic signaling in the PFC, contributing to PFC function though neuromodulator receptor crosstalk." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Novel Therapies for Cardiometabolic Disease: Recent Findings in Studies with Hormone...

    October 2022 Novel Therapies for Cardiometabolic Disease: Recent Findings in Studies with Hormone Peptide-Derived G Protein Coupled Receptor Agonists "The increasing prevalence of obesity and type 2 diabetes (T2DM) is provoking an important socioeconomic burden mainly in the form of cardiovascular disease (CVD). One successful strategy is the so-called metabolic surgery whose beneficial effects are beyond dietary restrictions and weight loss. One key underlying mechanism behind this surgery is the cooperative improved action of the preproglucagon-derived hormones, glucagon, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) which exert their functions through G protein-coupled receptors (GPCR). Great success has been reached with therapies based on the GLP-1 receptor monoagonism; therefore, a logical and rational approach is the use of the dual and triagonism of GCPC to achieve complete metabolic homeostasis. The present review describes novel findings regarding the complex biology of the preproglucagon-derived hormones, their signaling, and the drug development of their analogues, especially those acting as dual and triagonists. Moreover, the main investigations into animal models and ongoing clinical trials using these unimolecular dual and triagonists are included which have demonstrated their safety, efficacy, and beneficial effects on the CV system. These therapeutic strategies could greatly impact the treatment of CVD with unprecedented benefits which will be revealed in the next years." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Network pharmacological investigation into the mechanism of Kaixinsan powder for the treatment of...

    October 2022 Network pharmacological investigation into the mechanism of Kaixinsan powder for the treatment of depression "Kaixinsan powder (KXS), a classic prescription of traditional Chinese Medicine (TCM), is widely used in the treatment of depression, but its mechanism remains unclear. The network pharmacology method was used to constructe the "herb-component-target" network, and elucidated KXS potential mechanisms of action in the treatment of depression. Moreover, molecular docking was applied to valid the important interactions between the ingredients and the target protein. The "herb-component-target" network indicated that the ingredients of Girinimbin, Gomisin B and Asarone, and the protein targets of ESR, AR and NR3C1 mostly contribute to the antidepressant effect of KXS. KEGG pathway analysis highlighted the most significant pathways associated with depression treatment, including neuroactive ligand-receptor interaction pathway, serotonergic synapse pathway, PI3K-Akt signaling pathway and MAPK signaling pathway. Go enrichment analysis indicated that the mechanism of KXS in treating depression was involved in the biological process of GPCR signal transduction, hormone metabolism and nerve cell apoptosis. Moreover, molecular docking results showed that Polygalaxanthone III, Girinimbine and Pachymic acid performed greater binding ability with key antidepressant target 5-HTR. In conclusion, this study preliminarily revealed key active components in KXS, including Gomisin B, Asarone, Ginsenoside Rg1, Polygalaxanthone III and Pachymic acid, could interact with multiple targets (5-HTR, DR, ADRA, AR, ESR, NR3C1) and modulate the activation of multiple pathways (Neuroactive ligand -receptor interaction pathway, serotonergic synapse pathway, PI3K-Akt signaling pathway and MAPK signaling pathway)." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Diversification of PAR signaling through receptor crosstalk

    October 2022 "Protease activated receptors (PARs) are among the first receptors shown to transactivate other receptors: noticeably, these interactions are not limited to members of the same family, but involve receptors as diverse as receptor kinases, prostanoid receptors, purinergic receptors and ionic channels among others. In this review, we will focus on the evidence for PAR interactions with members of their own family, as well as with other types of receptors. We will discuss recent evidence as well as what we consider as emerging areas to explore; from the signalling pathways triggered, to the physiological and pathological relevance of these interactions, since this additional level of molecular cross-talk between receptors and signaling pathways is only beginning to be explored and represents a novel mechanism providing diversity to receptor function and play important roles in physiology and disease." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Comparative study of neuropeptide signaling systems in Hemiptera

    October 2022 "Numerous physiological processes in insects are tightly regulated by neuropeptides and their receptors. Although they form an ancient signaling system, there is still a great deal of variety in neuropeptides and their receptors among different species within the same order. Neuropeptides and their receptors have been documented in many hemipteran insects, but the differences among them have been poorly characterized. Commercial grapevines worldwide are plagued by the bug Daktulosphaira vitifoliae (Hemiptera: Sternorrhyncha). Here, 33 neuropeptide precursors and 48 putative neuropeptide G protein-coupled receptor (GPCR) genes were identified in D. vitifoliae. Their expression profiles at the probe and feeding stages reflected potential regulatory roles in probe behavior. By comparison, we found that the Releasing Hormone-Related Peptides (GnRHs) system of Sternorrhyncha was differentiated from those of the other 2 suborders in Hemiptera. Independent secondary losses of the adipokinetic hormone/corazonin-related peptide receptor (ACP) and corazonin (CRZ) occurred during the evolution of Sternorrhyncha. Additionally, we discovered that the neuropeptide signaling systems of Sternorrhyncha were very different from those of Heteroptera and Auchenorrhyncha, which was consistent with Sternorrhyncha's phylogenetic position at the base of the order. This research provides more knowledge on neuropeptide systems and sets the groundwork for the creation of novel D. vitifoliae management strategies that specifically target these signaling pathways." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Dr. GPCR Virtual Cafe with Matthew Eddy - New date!

    ☕ We are excited to announce our rescheduled Dr. GPCR Virtual Cafe session with Dr. Matthew E. on Friday, October 7th at 1 PM ET. Don't miss the chance to listen to his latest research on the field. It's a great opportunity to get warmed up for the upcoming Summit starting the next Monday. Get your ticket today on Eventbrite! ➡https://bit.ly/3CmntVn

  • Dr. GPCR Virtual Cafe - Postponed

    We are postponing the Dr. GPCR Virtual Cafe with Matthew Eddy scheduled for tomorrow (Sep 29th, 2022) due to Hurricane Ian that is affecting Florida. We will provide a new rescheduling date soon. #gpcr #drgpcr

  • Although the cannabinoid type-2 receptor (CB2) is highly expressed in the immune system, emerging...

    September 2022 Cannabinoid type-2 receptors: An emerging target for regulating schizophrenia-relevant brain circuits "Although the cannabinoid type-2 receptor (CB2) is highly expressed in the immune system, emerging evidence points to CB2 playing a key role in regulating neuronal function in the central nervous system. Recent anatomical studies, combined with electrophysiological studies, indicate that CB2 receptors are expressed in specific dopaminergic and glutamatergic brain circuits that are hyperactive in schizophrenia patients. The ability of CB2 receptors to inhibit dopaminergic and hippocampal circuits, combined with the anti-inflammatory effects of CB2 receptor activation, make this receptor an intriguing target for treating schizophrenia, a disease where novel interventions that move beyond dopamine receptor antagonists are desperately needed. The development of new CB2-related pharmacological and genetic tools, including the first small molecule positive allosteric modulator of CB2 receptors, has greatly advanced our understanding of this receptor. While more work is needed to further elucidate the translational value of selectively targeting CB2 receptors with respect to schizophrenia, the studies discussed below could suggest that CB2 receptors are anatomically located in schizophrenia-relevant circuits, where the physiological consequence of CB2 receptor activation could correct circuit-based deficits commonly associated with positive and cognitive deficits." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Developing the Cannabinoid Receptor 2 (CB2) pharmacopeia: past, present, and future

    August 2022 "Cannabinoid Receptor 2 (CB2) is a G protein-coupled receptor (GPCR) with considerable, though as yet unrealized, therapeutic potential. Promising preclinical data support the applicability of CB2 activation in autoimmune and inflammatory diseases, pain, neurodegeneration, and osteoporosis. A diverse pharmacopeia of cannabinoid ligands is available, which has led to considerable advancements in the understanding of CB2 function and extensive preclinical evaluation. However, until recently, most CB2 ligands were highly lipophilic and as such, not optimal for clinical application due to unfavorable physicochemical properties. A number of strategies have been applied to develop CB2 ligands to achieve closer to 'drug-like' properties and a few such compounds have now undergone clinical trials. We review the current state of CB2 ligand development and progress in optimizing physicochemical properties, understanding advanced molecular pharmacology such as functional selectivity, and clinical evaluation of CB2-targeting compounds." Read more at the source #DrGPCR #GPCR #IndustryNews

  • TRPM3 in the eye and in the nervous system - from new findings to novel mechanisms

    August 2022 "The calcium-permeable cation channel TRPM3 can be activated by heat and the endogenous steroid pregnenolone sulfate. TRPM3's best understood function is its role as a peripheral noxious heat sensor in mice. However, the channel is expressed in various tissues and cell types including neurons as well as glial and epithelial cells. TRPM3 expression patterns differ between species and change during development. Furthermore, a plethora of TRPM3 variants that result from alternative splicing have been identified and the majority of these isoforms are yet to be characterized. Moreover, the mechanisms underlying regulation of TRPM3 are largely unexplored. In addition, a micro-RNA gene (miR-204) is located within the TRPM3 gene. This complexity makes it difficult to obtain a clear picture of TRPM3 characteristics. However, a clear picture is needed to unravel TRPM3's full potential as experimental tool, diagnostic marker and therapeutic target. Therefore, the newest data related to TRPM3 have to be discussed and to be put in context as soon as possible to be up-to-date and to accelerate the translation from bench to bedside. The aim of this review is to highlight recent results and developments with particular focus on findings from studies involving ocular tissues and cells or peripheral neurons of rodents and humans." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Community guidelines for GPCR ligand bias: IUPHAR review 32

    August 2022 "GPCRs modulate a plethora of physiological processes and mediate the effects of one-third of FDA-approved drugs. Depending on which ligand activates a receptor, it can engage different intracellular transducers. This 'biased signalling' paradigm requires that we now characterize physiological signalling not just by receptors but by ligand-receptor pairs. Ligands eliciting biased signalling may constitute better drugs with higher efficacy and fewer adverse effects. However, ligand bias is very complex, making reproducibility and description challenging. Here, we provide guidelines and terminology for any scientists to design and report ligand bias experiments. The guidelines will aid consistency and clarity, as the basic receptor research and drug discovery communities continue to advance our understanding and exploitation of ligand bias. Scientific insight, biosensors, and analytical methods are still evolving and should benefit from and contribute to the implementation of the guidelines, together improving translation from in vitro to disease-relevant in vivo models." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Molecular insights into psychedelic drug action

    August 2022 "A confluence of factors has renewed interest in the scientific understanding and translational potential of psychedelic drugs such as lysergic acid diethylamide (LSD), mescaline, and psilocybin: the desire for additional approaches to mental health care, incremental progress in basic and clinical research, and the reconsideration and relaxation of existing drug policies. With the United States Food and Drug Administration's designation of psilocybin as a "Breakthrough Therapy" for treatment-resistant depression, a new path has been forged for the conveyance of psychedelics to the clinic. Essential to the further development of such applications, however, is a clearer understanding of how these drugs exert their effects at the molecular level. Here we review the current knowledge regarding the molecular details of psychedelic drug actions and suggest that these discoveries can facilitate new insights into their hallucinogenic and therapeutic mechanisms." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Molecular targets of psychedelic-induced plasticity

    August 2022 "Psychedelic research across different disciplines and biological levels is growing at a remarkably fast pace. In the prospect of a psychedelic drug becoming again an approved treatment, much of these efforts have been oriented toward exploring the relationship between the actual psychedelic effects and those manifestations of therapeutic interest. Considering the central role of the serotonin 5-HT2A receptor in the distinct effects of psychedelics in human psyche, neuropharmacology sits at the center of this debate and exploratory continuum. Here we discuss some of the most recent findings in human studies and contextualize them considering previous preclinical models studying phenomena related to synaptic plasticity. A special emphasis is placed on knowledge gaps, challenges, and limitations to evaluate the underpinnings of psychedelics' potential antidepressant action." Read more at the source #DrGPCR #GPCR #IndustryNews

  • AlphaFold2 versus experimental structures: evaluation on G protein-coupled receptors

    August 2022 "As important drug targets, G protein-coupled receptors (GPCRs) play pivotal roles in a wide range of physiological processes. Extensive efforts of structural biology have been made on the study of GPCRs. However, a large portion of GPCR structures remain unsolved due to structural instability. Recently, AlphaFold2 has been developed to predict structure models of many functionally important proteins including all members of the GPCR family. Herein we evaluated the accuracy of GPCR structure models predicted by AlphaFold2. We revealed that AlphaFold2 could capture the overall backbone features of the receptors. However, the predicted models and experimental structures were different in many aspects including the assembly of the extracellular and transmembrane domains, the shape of the ligand-binding pockets, and the conformation of the transducer-binding interfaces. These differences impeded the use of predicted structure models in the functional study and structure-based drug design of GPCRs, which required reliable high-resolution structural information." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Adenosine receptor signalling in Alzheimer's disease

    August 2022 "Alzheimer's disease (AD) is the most common dementia in the elderly and its increasing prevalence presents treatment challenges. Despite a better understanding of the disease, the current mainstay of treatment cannot modify pathogenesis or effectively address the associated cognitive and memory deficits. Emerging evidence suggests adenosine G protein-coupled receptors (GPCRs) are promising therapeutic targets for Alzheimer's disease. The adenosine A1 and A2A receptors are expressed in the human brain and have a proposed involvement in the pathogenesis of dementia. Targeting these receptors preclinically can mitigate pathogenic β-amyloid and tau neurotoxicity whilst improving cognition and memory. In this review, we provide an accessible summary of the literature on Alzheimer's disease and the therapeutic potential of A1 and A2A receptors. Although there are no available medicines targeting these receptors approved for treating dementia, we provide insights into some novel strategies, including allosterism and the targeting of oligomers, which may increase drug discovery success and enhance the therapeutic response." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Targeting CXCR1 and CXCR2 receptors in cardiovascular diseases

    August 2022 "CXCR1 and CXCR2 chemokine receptors, mainly activated by interleukin 8 (IL-8 or CXCL8), are expressed in a variety of cells including, leukocytes, fibroblasts, endothelial cells, and smooth muscle cells. Numerous intracellular mediators are activated by these G protein-coupled receptors based on several factors, including the nature of the ligand, its concentration, and the binding sites with the receptor, levels of the receptor, cell type, and stimulatory environment. Much focus is currently being directed towards CXCR1/2 inhibitors, as these receptors primarily induce the chemotaxis of leukocytes, especially neutrophils, during inflammation, a key process in cardiovascular disease (CVD) progression. CXCR1/2 inhibitors show beneficial effects in various animal models of CVD. These effects include reducing the atherosclerotic plaque area, improving the serum lipid profile, attenuation of the damage following ischemia-reperfusion, the regulation of blood pressure, and the restriction of cardiac remodeling. Based on these encouraging results, testing CXCR1/2 inhibitors in clinical trials could be of a great importance to limit the inflammatory complications associated with CVDs." Read more at the source #DrGPCR #GPCR #IndustryNews

  • GRK2 in cardiovascular disease and its potential as a therapeutic target

    August 2022 "Cardiovascular diseases (CVDs) represent the leading cause of death globally. Despite major advances in the field of pharmacological CVD treatments, particularly in the field of heart failure (HF) research, case numbers and overall mortality remain high and have trended upwards over the last few years. Thus, identifying novel molecular targets for developing HF therapeutics remains a key research focus. G protein-coupled receptors (GPCRs) are critical myocardial signal transducers which regulate cardiac contractility, growth, adaptation and metabolism. Additionally, GPCR dysregulation underlies multiple models of cardiac pathology, and most pharmacological therapeutics currently used in HF target these receptors. Currently-approved treatments have improved patient outcomes, but therapies to stop or reverse HF are lacking. A recent focus on GPCR intracellular-regulating proteins such as GPCR kinases (GRKs) has uncovered GRK2 as a promising target for combating HF. Current literature strongly establishes increased levels and activity of GRK2 in multiple models of CVD. Additionally, the GRK2 interactome includes numerous proteins which interact with differential domains of GRK2 to modulate both beneficial and deleterious signaling pathways in the heart, indicating that these domains can be targeted with a high level of specificity unique to various cardiac pathologies. These data support the premise that GRK2 should be at the forefront of a novel investigative drug search. This perspective reviews cardiac GPCRs, describes the structure and functions of GRK2 in cardiac function and maladaptive pathology, and summarizes the ongoing and future research for targeting this critical kinase across cellular, animal and human models of cardiac dysfunction and HF." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Posttranslational modifications in GPCR internalization

    August 2022 "G protein-coupled receptors (GPCRs) are the largest family of membrane receptors that serve as the most important drug targets. Classically, GPCR internalization has been considered to lead to receptor desensitization. However, many studies over the past decade have reported that internalized membrane receptors can trigger distinct signal activation. The "internalized activation" provides a completely new understanding for the receptor internalization, the mechanism of physiology/pathology and novel drug targets for precision medicine. GPCR internalization undergoes a series of strict regulations, especially by posttranslational modifications (PTMs). Here, this review summarizes different PTMs in GPCR internalization and analyzes their significance in GPCR internalization dynamics, internalization routes, postinternalization fates, and related diseases, which will offer new insights into the regulatory mechanism of GPCR signaling and novel drug targets for precision medicine." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Diversity and specificity in location-based signaling outputs of neuronal GPCRs

    August 2022 "The common mechanisms by which members of the G protein-coupled receptor (GPCR) family respond to neurotransmitters in the brain have been well studied. However, it is becoming increasingly clear that GPCRs show great diversity in their intracellular location, interacting partners and effectors, and signaling consequences. Here we will discuss recent studies on the diversity of location, effectors, and signaling of GPCRs, and how these could interact to generate specific spatiotemporal patterns of GPCR signaling in cells." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Deciphering the signaling mechanisms of β-arrestin1 and β-arrestin2 in regulation of cancer cell...

    August 2022 Deciphering the signaling mechanisms of β-arrestin1 and β-arrestin2 in regulation of cancer cell cycle and metastasis "β-Arrestins are ubiquitously expressed intracellular proteins with many functions which interact directly and indirectly with a wide number of cellular partners and mediate downstream signaling. Originally, β-arrestins were identified for their contribution to GPCR desensitization to agonist-mediated activation, followed by receptor endocytosis and ubiquitylation. However, current investigations have now recognized that in addition to GPCR arresting (hence the name arrestin). β-Arrestins are adaptor proteins that control the recruitment, activation, and scaffolding of numerous cytoplasmic signaling complexes and assist in G-protein receptor signaling, thus bringing them into close proximity. They have participated in various cellular processes such as cell proliferation, migration, apoptosis, and transcription via canonical and noncanonical pathways. Despite their significant recognition in several physiological processes, these activities are also involved in the onset and progression of various cancers. This review delivers a concise overview of the role of β-arrestins with a primary emphasis on the signaling processes which underlie the mechanism of β-arrestins in the onset of cancer. Understanding these processes has important implications for understanding the therapeutic intervention and treatment of cancer in the future." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Structural basis of GPCR coupling to distinct signal transducers: implications for biased signaling

    August 2022 "Three classes of G-protein-coupled receptor (GPCR) partners - G proteins, GPCR kinases, and arrestins - preferentially bind active GPCRs. Our analysis suggests that the structures of GPCRs bound to these interaction partners available today do not reveal a clear conformational basis for signaling bias, which would have enabled the rational design of biased GRCR ligands. In view of this, three possibilities are conceivable: (i) there are no generalizable GPCR conformations conducive to binding a particular type of partner; (ii) subtle differences in the orientation of individual residues and/or their interactions not easily detectable in the receptor-transducer structures determine partner preference; or (iii) the dynamics of GPCR binding to different types of partners rather than the structures of the final complexes might underlie transducer bias." Read more at the source #DrGPCR #GPCR #IndustryNews

  • Synthesis and characterization of an orally bioavailable small molecule agonist of the apelin recept

    August 2022 "The apelin receptor (APJ) is a target for cardiovascular indications. Previously, we had identified a novel pyrazole-based agonist 1 ((S)-N-(1-(cyclobutylamino)-1-oxo-5-(piperidin-1-yl)pentan-3-yl)-1-cyclopentyl-5-(2,6-dimethoxyphenyl)-1H-pyrazole-3-carboxamide hydrochloride) of this GPCR. Systematic modification of 1 was performed to produce compounds with improved potency and ADME properties. Orally bioavailable compound 47 with favorable agonist potency (Ca2+EC50 = 24 nM, cAMPi EC50 = 6.5 nM) and pharmacokinetic properties (clearance ∼20 mL/min/kg in rats) was identified. This compound has vastly reduced brain penetration and is devoid of significant off-target liability. In summary, a potent and selective APJ agonist suitable for in vivo studies of APJ in peripheral tissues after oral administration has been identified." Read more at the source #DrGPCR #GPCR #IndustryNews

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