August 2022 GRK2 selectively attenuates the neutrophil NADPH-oxidase response triggered by β-arrestin recruiting GPR84 agonists "In order to avoid a prolonged pro-inflammatory neutrophil response, signaling downstream of an agonist-activated G protein-coupled receptor (GPCR) has to be rapidly terminated. Among the family of GPCR kinases (GRKs) that regulate receptor phosphorylation and signaling termination, GRK2, which is highly expressed by immune cells, plays an important role. The medium chain fatty acid receptor GPR84 as well as formyl peptide receptor 2 (FPR2), receptors expressed in neutrophils, play a key role in regulating inflammation. In this study, we investigated the effects of GRK2 inhibitors on neutrophil functions induced by GPR84 and FPR2 agonists. GRK2 was shown to be expressed in human neutrophils and analysis of subcellular fractions revealed a cytosolic localization. " Read more at the source #DrGPCR #GPCR #IndustryNews

August 2022 "Epithelial tube formation requires Rho1-dependent actomyosin contractility to generate the cellular forces that drive cell shape changes and rearrangement. Rho1 signaling is activated by G-protein-coupled receptor (GPCR) signaling at the cell surface. During Drosophila embryonic salivary gland (SG) invagination, the GPCR ligand Folded gastrulation (Fog) activates Rho1 signaling to drive apical constriction. The SG receptor that transduces the Fog signal into Rho1-dependent myosin activation has not been identified. Here, we reveal that the Smog GPCR transduces Fog signal to regulate Rho kinase accumulation and myosin activation in the medioapical region of cells to control apical constriction during SG invagination. We also report on unexpected Fog-independent roles for Smog in maintaining epithelial integrity and organizing cortical actin. Our data support a model wherein Smog regulates distinct myosin pools and actin cytoskeleton in a ligand-dependent manner during epithelial tube formation." Read more at the source #DrGPCR #GPCR #IndustryNews

August 2022 "Emerging evidence suggests that G protein-coupled receptor (GPCR) kinases (GRKs) are associated with the pathophysiology of Alzheimer's disease (AD). However, GRKs have not been directly implicated in regulation of the amyloid-β (Aβ) pathogenic cascade in AD. Here, we determine that GRKs phosphorylate a non-canonical substrate, anterior pharynx-defective 1A (APH1A), an integral component of the γ-secretase complex. Significantly, we show that GRKs generate distinct phosphorylation barcodes in intracellular loop 2 (ICL2) and the C terminus of APH1A, which differentially regulate recruitment of the scaffolding protein β-arrestin 2 (βarr2) to APH1A and γ-secretase-mediated Aβ generation. Further molecular dynamics simulation studies reveal an interaction between the βarr2 finger loop domain and ICL2 and ICL3 of APH1A, similar to a GPCR-β-arrestin complex, which regulates γ-secretase activity. Collectively, these studies provide insight into the molecular and structural determinants of the APH1A-βarr2 interaction that critically regulate Aβ generation." Read more at the source #DrGPCR #GPCR #IndustryNews

August 2022 "The X-linked form of Kallmann syndrome (KS), characterized by hypogonadotropic hypogonadism and anosmia, is due to mutations in the ANOS1 gene that encodes for the extracellular matrix (ECM) protein anosmin 1. Prokineticins (PKs) exert their biological functions through the activation of the G protein-coupled receptors (GPCRs) prokineticin receptor 1 and 2 (PKR1, 2), and mutations in the PK2 and PKR2 genes are involved in the pathogenesis of KS. We have previously shown interaction between PKR2 and anosmin 1 in vitro. In the current report we present evidence of the modulation of PK2/PKR2 activity by anosmin 1, since this protein is able to enhance the activation of the ERK1/2 (extracellular signal-regulated kinase 1/2) pathway elicited by PK2 through PKR2. We also show that the N-terminal region of anosmin 1, capable of binding to the PK2-binding domain of PKR2, seems to be responsible for this effect. The whey acidic protein domain (WAP) is necessary for this modulatory activity, although data from GST pull-down (glutathione-S-transferase) and analysis of the N267K mutation in the fibronectin type III domain 1 (FnIII.1) suggest the cysteine-rich (CR) and the FnIII.1 domains could assist the WAP domain both in the binding to PKR2 and in the modulation of the activation of the receptor by PK2. Our data support the idea of a modulatory role of anosmin 1 in the biological effects controlled by the PK2/PKR2 system." Read more at the source #DrGPCR #GPCR #IndustryNews

August 2022 "The cannabinoid CB1 receptor is the most abundant G protein coupled receptor (GPCR) in the central nervous system, which mediates the functional response to endocannabinoids and Cannabis compounds. A variety of ligands for CB1 receptors have been developed as promising drug candidates for the treatment of neurological disorders. New high-resolution structures of CB1 receptor in different functional states have significantly improved our molecular understanding of CB1 ligand interactions, selectivity, receptor activation and allosteric modulation. These advances have paved the way for development of novel ligands for different therapeutic applications. In this review, we describe the structural determinants for modulation of CB1 receptors by different types of ligands, as well as the differences between CB1 and its homologous, the CB2 receptor. LINKED ARTICLES: This article is part of a themed issue on Structure Guided Pharmacology of Membrane Proteins (BJP 75th Anniversary). " Read more at the source #DrGPCR #GPCR #IndustryNews

August 2022 "Background: Activation of signaling effectors by G-protein coupled receptors (GPCRs) depends on different molecular mechanisms triggered by conserved amino acid residues. Although studies have focused on the G-protein signaling state, the mechanism for β-arrestin signaling by CB1 is not yet well defined. Studies have indicated that transmembrane helix 7 (TMH7) and the highly conserved NPXXY motif can be subject to different conformational changes in response to biased ligands and could therefore participate in a molecular mechanism to trigger β-arrestin recruitment. " Read more at the source #DrGPCR #GPCR #IndustryNews

August 2022 Gαs and Gαq/11 protein coupling bias of two AVPR2 mutants (R68W and V162A) that cause nephrogenic diabetes insipidus "Loss-of-function mutations of the arginine vasopressin receptor 2 gene (AVPR2) cause Nephrogenic diabetes insipidus (NDI). AVPR2 is a kind of G protein coupled receptor (GPCR) and mainly couples with Gαs protein leading to cAMP accumulation in the cell as a secondary messenger. Recent studies showed that some AVPR2 mutations could cause biased Gαq/11 protein coupling rather than Gαs. Investigation into the characterization of biased receptors may give insights into the relationship between the conformational change of the receptor because of the mutation and related downstream signaling. In this study, R68W and V162A were analyzed to whether they show a bias to Gαs or Gαq/11 proteins. Their functionality in terms of cAMP production via Gαs protein coupling was decreased compared to the wild-type receptor. On the other hand, they showed the ability to couple with Gαq/11 protein and make Ca2+ mobilization at different levels in the cell. R68W showed bias to coupling with Gαq/11 protein rather than V162A and wild-type receptor. Studies about the Gα protein coupling bias of mutant AVPR2s may broaden our understanding of the relationship between the changed conformation of the receptor and consequently activated signaling pathways, and also may shed light on the development of more effective new therapeutics." Read more at the source #DrGPCR #GPCR #IndustryNews

August 2022 Production of human A 2A AR in lipid nanodiscs for 19 F-NMR and single-molecule fluorescence spectroscopy "We describe production of the human A2A adenosine receptor (A2AAR), a class A G protein-coupled receptor (GPCR) for 19F-NMR and single-molecule fluorescence (SMF) spectroscopy. We explain in detail steps shared between the two sample preparation strategies, including expression and isolation of A2AAR and assembly of A2AAR in lipid nanodiscs and procedures for incorporation of either 19F-NMR or fluorescence probes. Protocols for SMF experiments include sample setup, data acquisition, data processing, and error analysis. For complete details on the use and execution of this protocol, please refer to Wei et al. (2022) and Sušac et al. (2018)." Read more at the source #DrGPCR #GPCR #IndustryNews

August 2022 Dopamine D 1 receptor-mediated β-arrestin signaling: Insight from pharmacology, biology, behavior, and neurophysiology "The awareness of the potential importance of functional selectivity/biased signaling has led to the discovery of biased compounds as both research tools and novel drugs. A major pan-receptor focus has been to identify GPCR-selective ligands that have bias in G protein-dependent vs. β-arrestin related signaling. Although this field has exploded during the past two decades, it is only recently that highly β-arrestin biased ligands for the dopamine D1 receptor were reported. We now summarize important pharmacological, molecular, and cellular studies relevant to D1-mediated β-arrestin-related signaling. It is intriguing that many results emerged from behavioral and physiological studies implying that bias toward or against D1-mediated β-arrestin either can improve or impair functional outcomes. We discuss the importance of understanding the translatability of cell and animal models to have more precise functional targeting to harness the value of this signaling pathway." Read more at the source #DrGPCR #GPCR #IndustryNews

August 2022 In vitro assays for the functional characterization of (psychedelic) substances at the serotonin receptor 5-HT2A R "Serotonergic psychedelics are substances that induce alterations in mood, perception, and thought, and have the activation of serotonin (5-HT) 2A receptors (5-HT2A Rs) as a main pharmacological mechanism. Besides their appearance on the (illicit) drug market, e.g. as new psychoactive substances, their potential therapeutic application is increasingly explored. This group of substances demonstrates a broad structural variety, leading to insufficiently described structure-activity relationships, hence illustrating the need for better functional characterization. This review therefore elaborates on the in vitro molecular techniques that have been used the most abundantly for the characterization of (psychedelic) 5-HT2A R agonists. More specifically, this review covers assays to monitor the canonical G protein signaling pathway (e.g. measuring G protein recruitment/activation, inositol phosphate accumulation, or Ca2+ mobilization), assays to monitor non-canonical G protein signaling (such as arachidonic acid release), assays to monitor β-arrestin recruitment or signaling, and assays to monitor receptor conformational changes. In particular, focus lies on the mechanism behind the techniques, and the specific advantages and challenges that are associated with these. Additionally, several variables are discussed that one should consider when attempting to compare functional outcomes from different studies, both linked to the specific assay mechanism and linked to its specific execution, as these may heavily impact the assay outcome." Read more at the source #DrGPCR #GPCR #IndustryNews 5-HT2AR, GPCR, hallucinogens, in vitro assay, psychedelics; serotonin.

August 2022 "Opioid receptors (ORs) represent one of the most significant groups of G-protein coupled receptor (GPCR) drug targets and also act as prototypical models for GPCR function. In a constant effort to develop drugs with less side effects, and tools to explore the ORs nature and function, various (poly)pharmacological ligand design approaches have been performed. That is, besides classical ligands, a great number of bivalent ligands (i. e. aiming on two distinct OR subtypes), univalent heteromer-selective ligands and bitopic and allosteric ligands have been synthesized for the ORs. The scope of our review is to present the most important of the aforementioned ligands, highlight their properties and exhibit the current state-of-the-art pallet of promising drug candidates or useful molecular tools for the ORs." Read more at the source #DrGPCR #GPCR #IndustryNews

🎙️ Episode 87 of the @DrGPCR podcast with Dr. Bianca Plouffe is available! Listen to her talk about her work and her transition to PI in Belfast. Watch the full video with a paid @DrGPCR Ecosystem membership or listen wherever you get your podcast for free ➡️https://bit.ly/3UdxgnR #gpcr #drgpcr

Did you know that each month we collect the most recent #GPCR publications and the newest Biotech/Pharma GPCR-related news? 🔔 Subscribe to our Dr. GPCR monthly newsletter for FREE! ➡️ https://bit.ly/3cCI4em #gpcr #drgpcr

📅 Our FREE Dr. GPCR Summit 2022 is less than a month away! Come live and breathe GPCRs with us and don’t forget to submit your abstract. The deadline is September 30th. Register today as a @DrGPCR site member to attend for Free! ➡️https://bit.ly/3Q7hlnT #gpcr #drgpcr

Episode 86 of the Dr. GPCR podcast with Dr. Nicole (Nicki) Perry-Hauser is now available What a fun chat! 📹Would you like to see the video? Subscribe to a Dr. GPCR Ecosystem paid membership to enjoy everything Dr. GPCR has! ➡️https://bit.ly/3TCJVQQ #gpcr #drgpcr

🧠Do you want to share your #GPCR knowledge? Come to Dr. GPCR Ecosystem and create a course on your favorite #GPCR research, technique and more… Available for Dr. GPCR Ecosystem paid memberships ➡️https://bit.ly/3R8ZZbo #gpcr #drgpcr

⚠️Mark your calendar for the Dr. GPCR Summit 2022 held between Oct. 10 - 16, it's FREE! Join the #GPCR movement by signing up now! ➡️ https://bit.ly/3cKMXlw #gpcr #drgpcr

📌Our mission is to bring together all key players under one umbrella to co-exist in the @DrGPCR Ecosystem. Let’s work better together. Join us now, it's FREE! ➡️ https://bit.ly/3wQNZDg #gpcr #drgpcr

👥We have many surprises in reserve for you at the next Dr. GPCR Summit 2022 held between October 10th and 16th. Dr. GPCR Summit is FREE for all Ecosystem site members! Become a member today, it's also free! ➡️ https://bit.ly/3wKZmfR #gpcr #drgpcr

Do you hustle around looking for information about your favorite #GPCR? No need for that anymore! Dr. GPCR has it for you! 🔔 Subscribe to our monthly newsletter for FREE! ➡️ https://bit.ly/3cCI4em #gpcr #drgpcr

The program of the Dr. GPCR Summit from October 10th to the 16th is taking shape. Check it out today but first become a Dr. GPCR Ecosystem site member, which is free! Sign up now ➡️ https://bit.ly/3eaO5PH #gpcr #drgpcr

Immerse yourself in the Dr. GPCR Ecosystem with a paid membership for extra benefits. Catch up with the latest #GPCR news, our monthly Virtual Cafe, and much more! Join the #GPCR movement today! ➡️ https://bit.ly/3SUkB8D

Episode 85 of the Dr. GPCR podcast is here! 🎧Hear Dr. Nicholas Holliday and how he has combined his university role with his leadership of Excellerate Bioscience as CSO. Watch the full video with a paid Dr. GPCR Ecosystem membership or listen wherever you get your podcast for free. ➡️https://bit.ly/3cESfPi

Did you know that you can enjoy a Dr. GPCR Ecosystem paid membership with extra benefits? Create your own group, watch the latest podcast video before everyone else or start a discussion in the forum. 🔬Join the #GPCR movement today! ➡️ https://www.ecosystem.drgpcr.com/plans-pricing #gpcr #drgpcr

🌟The Dr. GPCR event of the year is the 3rd edition of the Summit. Come join us from October 10 to 16 to hear about exciting #GPCR research from amazing speakers. Become a Dr. GPCR Ecosystem site member to attend the Summit, it’s free! ➡️ https://bit.ly/3SUkB8D #gpcr #drgpcr

September 2022 Signaling pathways activated by sea bass gonadotropin-inhibitory hormone peptides in COS-7 cells transfected with their cognate receptor "Results of previous studies provided evidence for the existence of a functional gonadotropin-inhibitory hormone (GnIH) system in the European sea bass, Dicentrarchus labrax , which exerted an inhibitory action on the brain-pituitary-gonadal axis of this species. Herein, we further elucidated the intracellular signaling pathways mediating in sea bass GnIH actions and the potential interactions with sea bass kisspeptin (Kiss) signaling. Although GnIH1 and GnIH2 had no effect on basal CRE-luc activity, they significantly decreased forskolin-elicited CRE-luc activity in COS-7 cells transfected with their cognate receptor GnIHR. Moreover, an evident increase in SRE-luc activity was noticed when COS-7 cells expressing GnIHR were challenged with both GnIH peptides, and this stimulatory action was significantly reduced by two inhibitors of the PKC pathway. Notably, GnIH2 antagonized Kiss2-evoked CRE-luc activity in COS-7 cells expressing GnIHR and Kiss2 receptor (Kiss2R). However, GnIH peptides did not alter NFAT-RE-luc activity and ERK phosphorylation levels. These data indicate that sea bass GnIHR signals can be transduced through the PKA and PKC pathways, and GnIH can interfere with kisspeptin actions by reducing its signaling. Our results provide additional evidence for the understanding of signaling pathways activated by GnIH peptides in teleosts, and represent a starting point for the study of interactions with multiple neuroendocrine factors on cell signaling." Read more at the source #DrGPCR #GPCR #IndustryNews

September 2022 "Given the promising clinical value of allosteric modulators of G protein-coupled-receptors (GPCRs), mechanistic understanding of how these modulators alter GPCR function is of significance. Here, we report the crystallographic and cryo-electron microscopy structures of the cannabinoid receptor CB1 bound to the positive allosteric modulator (PAM) ZCZ011. These structures show that ZCZ011 binds to an extrahelical site in the transmembrane 2 (TM2)-TM3-TM4 surface. Through (un)biased molecular dynamics simulations and mutagenesis experiments, we show that TM2 rearrangement is critical for the propagation of allosteric signals. ZCZ011 exerts a PAM effect by promoting TM2 rearrangement in favor of receptor activation and increasing the population of receptors that adopt an active conformation. In contrast, ORG27569, a negative allosteric modulator (NAM) of CB1, also binds to the TM2-TM3-TM4 surface and exerts a NAM effect by impeding the TM2 rearrangement. Our findings fill a gap in the understanding of CB1 allosteric regulation and could guide the rational design of CB1 allosteric modulators." Read more at the source #DrGPCR #GPCR #IndustryNews

September 2022 "Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) lipids have been shown to stabilize an active conformation of class A G-protein coupled receptors (GPCRs) through a conserved binding site, not present in class B GPCRs. For class B GPCRs, previous molecular dynamics (MD) simulation studies have shown PI(4,5)P2 interacting with the Glucagon receptor (GCGR), which constitutes an important target for diabetes and obesity therapeutics. In this work, we applied MD simulations supported by native mass spectrometry (nMS) to study lipid interactions with GCGR. We demonstrate how tail composition plays a role in modulating the binding of PI(4,5)P2 lipids to GCGR. Specifically, we find the PI(4,5)P2 lipids to have a higher affinity toward the inactive conformation of GCGR. Interestingly, we find that in contrast to class A GPCRs, PI(4,5)P2 appear to stabilize the inactive conformation of GCGR through a binding site conserved across class B GPCRs but absent in class A GPCRs. This suggests differences in the regulatory function of PI(4,5)P2 between class A and class B GPCRs." Read more at the source #DrGPCR #GPCR #IndustryNews