G protein-coupled receptors (GPCRs) play a crucial role in cell function by transducing signals from the extracellular environment to the inside of the cell. They mediate the effects of various stimuli, including hormones, neurotransmitters, ions, photons, food tastants and odorants, and are renowned drug targets. Advancements in structural biology techniques, including X-ray crystallography and cryo-electron microscopy (cryo-EM), have driven the elucidation of an increasing number of GPCR structures. These structures reveal novel features that shed light on receptor activation, dimerization and oligomerization, dichotomy between orthosteric and allosteric modulation, and the intricate interactions underlying signal transduction, providing insights into diverse ligand-binding modes and signalling pathways. However, a substantial portion of the GPCR repertoire and their activation states remain structurally unexplored. Future efforts should prioritize capturing the full structural diversity of GPCRs across multiple dimensions. To do so, the integration of structural biology with biophysical and computational techniques will be essential. We describe in this review the progress of nuclear magnetic resonance (NMR) to examine GPCR plasticity and conformational dynamics, of atomic force microscopy (AFM) to explore the spatial-temporal dynamics and kinetic aspects of GPCRs, and the recent breakthroughs in artificial intelligence for protein structure prediction to characterize the structures of the entire GPCRome. In summary, the journey through GPCR structural biology provided in this review illustrates how far we have come in decoding these essential proteins architecture and function. Looking ahead, integrating cutting-edge biophysics and computational tools offers a path to navigating the GPCR structural landscape, ultimately advancing GPCR-based applications. LINKED ARTICLES: This article is part of a themed issue Complexity of GPCR Modulation and Signaling (ERNST). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.14/issuetoc.
- MeSH
- Protein Conformation MeSH
- Humans MeSH
- Receptors, G-Protein-Coupled * chemistry metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Chalcones, potential anticancer agents, have shown promise in the suppression of multidrug resistance due to the inhibition of drug efflux driven by certain adenosine triphosphate (ATP)-binding cassette (ABC) transporters. The gene and protein expression of chosen ABC transporters (multidrug resistance protein 1, ABCB1; multidrug resistance-associated protein 1, ABCC1; and breast cancer resistance protein, ABCG2) in human colorectal cancer cells (COLO 205 and COLO 320, which overexpress active ABCB1) was mainly studied in this work under the influence of a novel synthetic acridine-based chalcone, 1C. While gene expression dropped just at 24 h, compound 1C selectively suppressed colorectal cancer cell growth and greatly lowered ABCB1 protein levels in COLO 320 cells at 24, 48, and 72 h. It also reduced ABCC1 protein levels after 48 h. Molecular docking and ATPase tests show that 1C probably acts as an allosteric modulator of ABCB1. It also lowered galectin-1 (GAL1) expression in COLO 205 cells at 24 h. Functional tests on COLO cells revealed ABCB1 and ABCC1/2 to be major contributors to multidrug resistance in both. Overall, 1C transiently lowered GAL1 in COLO 205 while affecting important functional ABC transporters, mostly ABCB1 and to a lesser extent ABCC1 in COLO 320 cells. COLO 320's absence of GAL1 expression points to a possible yet unknown interaction between GAL1 and ABCB1.
- MeSH
- ATP Binding Cassette Transporter, Subfamily G, Member 2 metabolism MeSH
- ATP-Binding Cassette Transporters * metabolism chemistry genetics MeSH
- Acridines * chemistry pharmacology MeSH
- Chalcone * pharmacology chemistry MeSH
- Chalcones * pharmacology chemistry MeSH
- Drug Resistance, Neoplasm drug effects MeSH
- Colorectal Neoplasms metabolism drug therapy MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- ATP Binding Cassette Transporter, Subfamily B metabolism genetics MeSH
- Cell Proliferation drug effects MeSH
- Multidrug Resistance-Associated Protein 2 MeSH
- Multidrug Resistance-Associated Proteins metabolism genetics MeSH
- Antineoplastic Agents * pharmacology chemistry MeSH
- Gene Expression Regulation, Neoplastic drug effects MeSH
- Molecular Docking Simulation MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
INTRODUCTION: Multiple Sclerosis (MS), a debilitating central nervous system (CNS) disorder, is characterized by inflammation, demyelination, and neuronal degeneration. Despite advancements in immunomodulatory treatments, neuroprotective or restorative strategies remain inadequate. Our research is focusing on the potential of the positive allosteric modulator of AMPA receptors (AMPA-PAM), PF4778574, in addressing MS symptoms. METHODS: We utilized the MOG35-55 induced experimental autoimmune encephalomyelitis (EAE) model in C57BL6J mice to examine PF4778574's therapeutic and prophylactic efficacy. Our comprehensive approach included clinical scoring, optical coherence tomography (OCT), optomotor response (OMR) and histological assessments. Additionally, we explored the effects of PF4778574 in comparison and in combination with the immunomodulatory agent fingolimod, and investigated the impact on Cuprizone induced toxic demyelination. RESULTS: Prophylactic administration of PF4778574 showed notable improvement in clinical EAE indices and reduction in neuronal loss. While it did not diminish microglial activity, it reduced demyelinated areas in optic nerves and in the corpus callosum. Both PF4778574 and fingolimod significantly enhanced clinical EAE scores and decreased demyelination. However, their combination did not yield additional benefits. In the cuprizone model, PF4778574 increased oligodendrocyte precursor and mature myelin-forming cells, suggesting a pro-remyelinating effect. DISCUSSION: PF4778574 demonstrates promise in mitigating EAE effects, especially in terms of clinical disability and demyelination. These results suggest AMPA-PAMs as potential targets of interest for MS treatment beyond immunomodulatory approaches.
- MeSH
- Allosteric Regulation MeSH
- Receptors, AMPA * metabolism MeSH
- Demyelinating Diseases drug therapy metabolism MeSH
- Encephalomyelitis, Autoimmune, Experimental * drug therapy metabolism immunology MeSH
- Fingolimod Hydrochloride pharmacology therapeutic use MeSH
- Disease Models, Animal MeSH
- Mice, Inbred C57BL * MeSH
- Mice MeSH
- Multiple Sclerosis * drug therapy metabolism immunology MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Monocyclic monoterpenoids carvones have been recently identified as atypical negative allosteric modulators of aryl hydrocarbon receptor (AhR). In the current work, we performed AhR antagonist activity screening of 100 natural and synthetic monoterpenoids, and their analogues. Using SAR approach, structural determinants of AhR antagonist activity were assigned, including CO presence/position, planarity, and C3/C5-alkylation. Applying pyramidal selection criteria, including absence of residual agonist activity, no cytotoxicity, strong antagonist potency, and pan-antagonism against diverse AhR agonists, we distilled four lead AhR antagonists (carvacrol, o-cresol, 3-methyl-S-carvone, EN-2). Whereas 3-methyl-S-carvone and EN-2 were non-competitive AhR pan-antagonists, carvacrol and o-cresol were ligand-selective AhR antagonists acting by unclear mechanism. We characterized in detail the effects of lead compounds at cellular functions of AhR, including AhR nuclear translocation, AhR dimerization with ARNT, and the expression of AhR-regulated genes. As a proof of concept, effects of monoterpenoids in the murine macrophages were investigated.
- MeSH
- Humans MeSH
- Molecular Structure MeSH
- Monoterpenes * pharmacology chemistry chemical synthesis MeSH
- Mice MeSH
- Receptors, Aryl Hydrocarbon * metabolism antagonists & inhibitors MeSH
- Dose-Response Relationship, Drug MeSH
- Structure-Activity Relationship MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
The Sec translocon is a highly conserved membrane assembly for polypeptide transport across, or into, lipid bilayers. In bacteria, secretion through the core channel complex-SecYEG in the inner membrane-is powered by the cytosolic ATPase SecA. Here, we use single-molecule fluorescence to interrogate the conformational state of SecYEG throughout the ATP hydrolysis cycle of SecA. We show that the SecYEG channel fluctuations between open and closed states are much faster (~20-fold during translocation) than ATP turnover, and that the nucleotide status of SecA modulates the rates of opening and closure. The SecY variant PrlA4, which exhibits faster transport but unaffected ATPase rates, increases the dwell time in the open state, facilitating pre-protein diffusion through the pore and thereby enhancing translocation efficiency. Thus, rapid SecYEG channel dynamics are allosterically coupled to SecA via modulation of the energy landscape, and play an integral part in protein transport. Loose coupling of ATP-turnover by SecA to the dynamic properties of SecYEG is compatible with a Brownian-rachet mechanism of translocation, rather than strict nucleotide-dependent interconversion between different static states of a power stroke.
- MeSH
- Adenosine Triphosphate metabolism MeSH
- Adenosine Triphosphatases genetics metabolism MeSH
- Bacterial Proteins * metabolism MeSH
- Nucleotides metabolism MeSH
- SecA Proteins metabolism MeSH
- Escherichia coli Proteins * metabolism MeSH
- SEC Translocation Channels chemistry MeSH
- Protein Transport MeSH
- Publication type
- Journal Article MeSH
The transient receptor potential ion channel TRPA1 is a Ca2+-permeable nonselective cation channel widely expressed in sensory neurons, but also in many nonneuronal tissues typically possessing barrier functions, such as the skin, joint synoviocytes, cornea, and the respiratory and intestinal tracts. Here, the primary role of TRPA1 is to detect potential danger stimuli that may threaten the tissue homeostasis and the health of the organism. The ability to directly recognize signals of different modalities, including chemical irritants, extreme temperatures, or osmotic changes resides in the characteristic properties of the ion channel protein complex. Recent advances in cryo-electron microscopy have provided an important framework for understanding the molecular basis of TRPA1 function and have suggested novel directions in the search for its pharmacological regulation. This chapter summarizes the current knowledge of human TRPA1 from a structural and functional perspective and discusses the complex allosteric mechanisms of activation and modulation that play important roles under physiological or pathophysiological conditions. In this context, major challenges for future research on TRPA1 are outlined.
- MeSH
- Allosteric Regulation MeSH
- Cryoelectron Microscopy methods MeSH
- Transient Receptor Potential Channels metabolism chemistry physiology MeSH
- TRPA1 Cation Channel * metabolism chemistry physiology MeSH
- Humans MeSH
- Structure-Activity Relationship MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Natural products are widely used in different aspects of our lives - from household cleaners and food production, via cosmetics and aromatherapy, to both alternative and traditional medicine. In our research group, we have recently described several monoterpenoids with potential in the antiviral and anticancer therapy by allosteric targeting of aryl hydrocarbon receptor (AhR). Prior to any practical application, biological effects on human organism must be taken in concern. This review article is focused on the biological effects of 5 monoterpenoids on the human health previously identified as AhR antagonists with a therapeutic potential as antiviral and anticancer agents. We have thoroughly described cytotoxic, anti-inflammatory, anti-proliferative, and anticancer effects, as well as known interactions with nuclear receptors. As clearly demonstrated, monoterpenoids in general represent almost an inexhaustible reservoir of natural compounds possessing the ability to influence, modulate and improve human health.
- MeSH
- Antiviral Agents pharmacology therapeutic use chemistry MeSH
- Humans MeSH
- Monoterpenes * pharmacology chemistry therapeutic use MeSH
- Neoplasms drug therapy metabolism MeSH
- Antineoplastic Agents pharmacology therapeutic use MeSH
- Receptors, Aryl Hydrocarbon * metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Muscarinic acetylcholine receptors are metabotropic G-protein coupled receptors. Muscarinic receptors in the cardiovascular system play a central role in its regulation. Particularly M2 receptors slow down the heart rate by reducing the impulse conductivity through the atrioventricular node. In general, activation of muscarinic receptors has sedative effects on the cardiovascular system, including vasodilation, negative chronotropic and inotropic effects on the heart, and cardioprotective effects, including antifibrillatory effects. First, we review the signaling of individual subtypes of muscarinic receptors and their involvement in the physiology and pathology of the cardiovascular system. Then we review age and disease-related changes in signaling via muscarinic receptors in the cardiovascular system. Finally, we review molecular mechanisms involved in cardioprotection mediated by muscarinic receptors leading to negative chronotropic and inotropic and antifibrillatory effects on heart and vasodilation, like activation of acetylcholine-gated inward-rectifier K+-currents and endothelium-dependent and -independent vasodilation. We relate this knowledge with well-established cardioprotective treatments by vagal stimulation and muscarinic agonists. It is well known that estrogen exerts cardioprotective effects against atherosclerosis and ischemia-reperfusion injury. Recently, some sex hormones and neurosteroids have been shown to allosterically modulate muscarinic receptors. Thus, we outline possible treatment by steroid-based positive allosteric modulators of acetylcholine as a novel pharmacotherapeutic tactic. Keywords: Muscarinic receptors, Muscarinic agonists, Allosteric modulation, Cardiovascular system, Cardioprotection, Steroids.
Mavakamten je selektivní, alosterický a reverzibilní inhibitor srdečního myozinu. Tímto způsobem moduluje počet myozinových hlavic, které mohou vstupovat do stavu vzniku kontrakce, a tím snižuje pravděpodobnost tvorby systolických a reziduálních diastolických příčných můstků při kontrakci. Látka je aktuálně schválená a indikovaná k léčbě symptomatické hypertrofické obstrukční kardiomyopatie (oHCM) (New York Heart Association, NYHA, třída II–III) u dospělých pacientů. Aktuálně probíhá velká klinická studie, která se pokusí doplnit dlouhodobá data o bezpečnosti a účinnosti mavakamtenu ve zmíněné indikaci.
Mavakamten is a selective, allosteric and reversible inhibitor of cardiac myosin. In this way, it modulates the number of myosin heads that enter the state of onset of contraction, thereby reduce the likelihood of the formation of systolic and residual diastolic cross bridges during contraction. The molecule is currently approved and indicated for the treatment of symptomatic hypertrophic obstructive cardiomyopathy (oHCM) (New York Heart Association, NYHA, class II-III) in adult patients. A large clinical study is currently underway, which will attempt to supplement the long-term data on the safety and efficacy of mavacamten in the mentioned indication.
- Keywords
- mavakamten, inhibitory srdečního myozinu,
- MeSH
- Data Analysis MeSH
- Drug Evaluation MeSH
- Cardiomyopathy, Hypertrophic * diagnosis drug therapy MeSH
- Clinical Studies as Topic MeSH
- Cardiac Myosins * antagonists & inhibitors pharmacokinetics pharmacology therapeutic use MeSH
- Publication type
- Review MeSH
Transient receptor potential melastatin (TRPM) channels, a subfamily of the TRP superfamily, constitute a diverse group of ion channels involved in mediating crucial cellular processes like calcium homeostasis. These channels exhibit complex regulation, and one of the key regulatory mechanisms involves their interaction with calmodulin (CaM), a cytosol ubiquitous calcium-binding protein. The association between TRPM channels and CaM relies on the presence of specific CaM-binding domains in the channel structure. Upon CaM binding, the channel undergoes direct and/or allosteric structural changes and triggers down- or up-stream signaling pathways. According to current knowledge, ion channel members TRPM2, TRPM3, TRPM4, and TRPM6 are directly modulated by CaM, resulting in their activation or inhibition. This review specifically focuses on the interplay between TRPM channels and CaM and summarizes the current known effects of CaM interactions and modulations on TRPM channels in cellular physiology.
