Molecular Pharmacology最新文献

{"title":"Rational design of biased G protein-coupled receptor agonists.","authors":"Vsevolod V Gurevich","doi":"10.1016/j.molpha.2025.100089","DOIUrl":"10.1016/j.molpha.2025.100089","url":null,"abstract":"<p><p>Activation of most G protein-coupled receptors (GPCRs) initiates several branches of signaling. The consequences of some of these can be therapeutically beneficial, whereas others may cause unwanted side effects. Therefore, search for ligands biasing receptor signaling toward desired directions and away from undesired ones is increasingly popular. Currently, the field is focusing on G protein versus arrestin dichotomy. Arrestin binding to most GPCRs critically depends on receptor phosphorylation by GPCR kinases (GRKs). Existing data suggest that to bias signaling for or against arrestin-mediated branches one needs to enhance or reduce, respectively, the propensity of the receptor to recruit GRKs and become phosphorylated. As GRKs are gatekeepers for arrestin-mediated signaling, rational design of biased ligands should be based on the comparison of receptor complexes with G proteins with the structures of GPCRs bound to GRKs rather than arrestins. The same GPCR may engage distinct GRK subtypes differently, establishing an additional layer of bias. SIGNIFICANCE STATEMENT: Because arrestin binding to G protein-coupled receptors (GPCRs) requires prior receptor phosphorylation, GPCR-GPCR kinase complexes, not GPCR complexes with arrestins, should be compared to GPCR-G protein complexes to guide the design of G protein- and arrestin-biased ligands.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"107 12","pages":"100089"},"PeriodicalIF":3.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12799398/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145687537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LZ-106 inhibits anchorage-independent growth of non-small cell lung cancer cells by a positive feedback between reactive oxygen species induction and autophagy flux blockage.","authors":"Ruixuan Wang, Jingyuan Feng, Fei Meng, Yushi Chen, Siyu Chen, Xinru Wang, Xin Dai, Qinglong Guo, Jingfang Sun, Lin Yang","doi":"10.1016/j.molpha.2025.100078","DOIUrl":"10.1016/j.molpha.2025.100078","url":null,"abstract":"<p><p>Metastasis remains a formidable challenge in the treatment of non-small cell lung cancer (NSCLC), necessitating novel therapeutic strategies targeting anchorage-independent growth (AIG). This study investigates the inhibitory effects of LZ-106, a quinolone analog and potential therapeutic candidate for NSCLC, on AIG and metastasis. Through a series of in vitro and in vivo experiments, LZ-106 is demonstrated to induce anoikis in NSCLC cells, inhibiting their AIG ability. Mechanistically, LZ-106 disrupts autophagic flux, leading to the accumulation of autophagosomes and the promotion of anoikis. Additionally, LZ-106 elevates reactive oxygen species (ROS) levels, further enhancing anoikis in NSCLC cells under AIG conditions. Notably, a positive feedback loop between ROS induction and autophagy flux blockage is identified, reinforcing LZ-106's inhibitory effects on AIG and metastasis. In vivo studies corroborate LZ-106's antimetastatic efficacy, highlighting its potential as a promising therapeutic agent for NSCLC. Together, these findings nominate LZ-106 as a promising antimetastatic candidate and underscore a targetable ROS-autophagy axis for therapeutic development in NSCLC. SIGNIFICANCE STATEMENT: LZ-106 inhibits anchorage-independent growth and metastasis of non-small cell lung cancer by triggering a positive feedback loop between reactive oxygen species overproduction and autophagic flux blockade, causing autophagosome accumulation and anoikis. In vitro and in vivo data nominate LZ-106 and the reactive oxygen species-autophagy axis as therapeutic targets.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"107 11","pages":"100078"},"PeriodicalIF":3.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145329580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emerging voices in G protein-coupled receptor biology.","authors":"John Janetzko, Nicole A Perry-Hauser","doi":"10.1016/j.molpha.2025.100083","DOIUrl":"10.1016/j.molpha.2025.100083","url":null,"abstract":"","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"107 11","pages":"100083"},"PeriodicalIF":3.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145409445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mice carrying the human dopamine D2 receptor pathogenic mutation p.Met374Arg exhibit hyperactivity and aberrant D2 receptor function.","authors":"Dayana Rodriguez-Contreras, Joseph J Lebowitz, Cheryl Reed, Elizabeth Walker-Ziegler, David C Buck, Guochuan Li, Shu Xie, Yulong Li, Lev M Fedorov, Tamara J Phillips, John T Williams, Kim A Neve","doi":"10.1016/j.molpha.2025.100080","DOIUrl":"10.1016/j.molpha.2025.100080","url":null,"abstract":"<p><p>Two human dopamine D2 receptor mutations cause dominant hyperkinetic movement disorders. The phenotype of carriers of the DRD2 variant c.634A>T, p.Ile212Phe (D2-I212F) is less severe than that of carriers of the variant c.1121 T>G, p.Met374Arg (D2-M^6.36R). Both are gain-of-function mutations with respect to G protein-mediated signaling; however, D2-M^6.36R exhibits greater gain-of-function than D2-I212F, suggesting that this is a major contributor to pathogenicity. Drd2^I212F knock-in mice exhibit altered D2 receptor function consistent with the clinical phenotype. We now report that mice carrying the mutation D2-M^6.36R, Drd2^M6.36R knock-in mice, exhibited gait abnormalities and a 2-fold increase in locomotor activity, and females fell more quickly from an accelerating rotarod. Electrically evoked inhibitory postsynaptic conductances in midbrain dopamine neurons from heterozygous Drd2^M6.36R mice were prolonged compared with both Drd2^I212F and wild-type (WT) mice. Electrically evoked release of acetylcholine and dopamine was similar in neostriatal slices from Drd2^M6.36R, Drd2^I212F, and WT mice. Inhibition of acetylcholine release by the D2 receptor agonist quinpirole was decreased by approximately 25% relative to WT mice in slices from either heterozygous knock-in mouse, whereas reversal by sulpiride was reduced by approximately 40% only in Drd2^M6.36R+/- mice. Although the postsynaptic current measured in dopamine cell bodies was dramatically prolonged in Drd2^M6.36R mice, quinpirole inhibition of dopamine release in the striatum was not altered. This could reflect differences between axonal and somatodendritic compartments or between responses proximal to and distal from the receptor. The results support a pathogenic role for these D2 receptor point mutations in mouse models of human hyperkinetic disorders. SIGNIFICANCE STATEMENT: Two dopamine receptor mutations cause movement disorders. Both are activating mutations; however, D2-M^6.36R is activated more than D2-I212F, paralleling the more severe phenotype of D2-M^6.36R in people. The phenotype of mice with D2-M^6.36R is also more severe. These mice will help develop drug therapy.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"107 11","pages":"100080"},"PeriodicalIF":3.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13095426/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145355570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distinctive patterns of G protein coupling induced by the structurally similar 5-HT_2A receptor ligands ketanserin and altanserin in human prefrontal cortex.","authors":"Patricia Miranda-Azpiazu, Carolina Muguruza, Tomasz Maciej Stepniewski, Itziar Muneta-Arrate, David Moreira, José Brea, Luis F Callado, María Isabel Loza, Javier González-Maeso, Jana Selent, Rebeca Diez-Alarcia, J Javier Meana","doi":"10.1016/j.molpha.2025.100075","DOIUrl":"10.1016/j.molpha.2025.100075","url":null,"abstract":"<p><p>Antipsychotic activity of certain 5-HT_2A receptor (5-HT_2AR) antagonists has been attributed to inverse agonism. 5-HT_2AR hallucinogenic agonists exhibit biased agonism toward G_i/o proteins. Ketanserin and altanserin are 2 structurally similar orthosteric drugs used as 5-HT_2AR therapeutic and radiotracers tools. This study assessed the pharmacological properties of ketanserin and altanserin, previously described as neutral 5-HT_2AR antagonists, using postmortem human prefrontal cortex. Receptor radioligand binding experiments and functional [³⁵S]GTPγS (sulfur 35 labeled guanosine-5'-O-[gamma-thio]-triphosphate) binding assays followed by immunocapture with anti-Gα_q/11 and anti-Gα_i1 protein antibodies were performed. Molecular dynamics simulations were used to ascertain binding modes to the 5-HT_2AR. [³H]Ketanserin binding to 5-HT_2ARs was decreased by guanylyl-5'-imido-diphosphate, a GTP analog. Guanylyl-5'-imido-diphosphate transformed the biphasic inhibition of [³H]ketanserin binding by the agonist (±)DOI into a monophasic low-affinity curve. Ketanserin stimulated [³⁵S]GTPγS binding to Gα_q/11 but not Gα_i1 proteins. Conversely, altanserin inhibited [³⁵S]GTPγS binding to Gα_i1 but not Gα_q/11 proteins. These effects were blocked by the neutral antagonist MDL-11,939. Altanserin-induced inhibition was abolished by the Gα_i/o alkylating agent N-ethylmaleimide. Similar findings were observed in wild type but disappeared in 5-HT_2AR knockout mice. Ketanserin and altanserin showed distinct interactions within residues S2.61, S5.46, and N6.55 in the 5-HT_2AR binding pocket. Therefore, ketanserin and altanserin elicit biased signaling with different patterns of G protein modulation upon interacting with 5-HT_2ARs in brain. Ketanserin behaves as partial agonist on G_q/11, whereas altanserin acts as inverse agonist on G_i1 proteins. These findings should influence the design of antipsychotic drugs targeting this receptor and when used as antagonists and radiotracers for the 5-HT_2AR assessment. SIGNIFICANCE STATEMENT: Ketanserin and altanserin are categorized as neutral 5-HT_2A receptor antagonists. This study shows differential patterns of 5-HT_2A receptor coupling to Gα_q/11 and Gα_i1 proteins between ketanserin and altanserin and demonstrates biased signaling and inverse agonism in human brain.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"107 11","pages":"100075"},"PeriodicalIF":3.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12799460/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145368279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrophysiological characterization of the state-dependent inhibition of Kv7.1 and I_Ks by UCL2077.","authors":"Daniel Sastre, Efthimios Kyriakis, Julia Schauer, Magnus Chan, Ying Dou, Jodene Eldstrom, David Fedida","doi":"10.1016/j.molpha.2025.100076","DOIUrl":"10.1016/j.molpha.2025.100076","url":null,"abstract":"<p><p>In cardiomyocytes, Kv7.1 associates with the regulatory subunit KCNE1 to generate the delayed rectifier potassium current I_Ks, which plays a crucial role in cardiac repolarization at elevated heart rates. Gain-of-function mutations in either of these subunits are associated with short QT syndrome, a condition that increases the risk of cardiac arrhythmias including atrial fibrillation, syncope, and sudden death. Therefore, the study of pharmacological inhibitors of Kv7.1 and I_Ks is of significant therapeutic interest. In this work, we used whole-cell patch clamp recordings to characterize the electrophysiological effects of the Kv7.1 blocker 3-(triphenylmethylaminomethyl)pyridine (UCL2077) in both Kv7.1 and I_Ks (Kv7.1 + KCNE1) channels. We found that UCL2077 inhibited both Kv7.1 and I_Ks channels with high affinity (IC₅₀ in the picomolar range) and mild voltage dependence. The drug induced a biphasic time-dependent current decay and reduced current reactivation of Kv7.1, whereas the kinetics of I_Ks were unaffected. We examined state dependence using mutations that functionally stabilize Kv7.1/I_Ks in either the intermediate-open (E160R/R231E) or in the activated-open (E160R/R237E) state. In both channels, UCL2077 potency correlated with the strength of the electromechanical coupling. Our results are further supported by a kinetic Markov model simulating UCL2077 binding that closely resembles the experimental currents. Overall, our work provides an in-depth characterization of UCL2077's action on Kv7.1 and I_Ks channels, offering valuable insights for the development of Kv7.1/I_Ks inhibitors in the context of short QT syndrome and other cardiac arrhythmias. SIGNIFICANCE STATEMENT: This study characterizes UCL2077: a highly specific, high-affinity inhibitor of Kv7.1 and I_Ks channels with therapeutic implications for cardiac arrhythmia. Our work reveals a picomolar affinity, mild voltage dependence, and a kinetic modulation consistent with state-dependent open-channel block.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"107 11","pages":"100076"},"PeriodicalIF":3.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12799529/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145426949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting compounds that interact with the 2 known agonist-induced conformations of the human β1-adrenoceptor.","authors":"Jillian G Baker, Victor Jun Yu Lim, Richard G W Proudman, Franziska N Z Giese, Peter Kolb","doi":"10.1016/j.molpha.2025.100081","DOIUrl":"10.1016/j.molpha.2025.100081","url":null,"abstract":"<p><p>The β1-adrenoceptor exists in at least 2 agonist-stabilized conformational ensembles: a \"catecholamine\" ensemble induced via the intrahelical binding site through which catecholamines and most agonists act and a \"secondary\" ensemble of conformations through which CGP12177 stimulates agonist responses. Several β-ligands stimulate agonist responses through both conformations, resulting in biphasic concentration responses, but little is known about the structure-activity relationship of such ligands. Using a structure-activity hypothesis built on the predicted poses CGP12177 and 3 biphasic agonists (alprenolol, oxprenolol, and bucindolol), predictions based on ligand similarity and structural compatibility reasoning were made about 11 other β1-ligands not yet tested for secondary conformation interaction and examined in radioligand binding and functional assays using human β1- and β2-adrenoceptors. Although the predictions matched with pharmacology in only 6/11 of cases, 3 novel compounds were found to induce an active-state secondary conformation. A CGP12177 derivative (methyl-pyrrole replacing the cyclic urea motif) retained catecholamine site antagonism with secondary site activation. Carteolol (related to CGP12177) and bunitrolol (similar to alprenolol) activated both conformations with biphasic concentration responses. Bunolol (CGP12177 derivative lacking nitrogen in the bicyclic system), as predicted, was a neutral antagonist with no secondary site activation. Moprolol and some bucindolol analogs appeared as conventional agonists, whereas other alprenolol and bucindolol analogs lost all receptor interaction. In a β1-adrenoceptor mutant (β1-V189T-L195Q-W199Y) where secondary site CGP12177 and pindolol interaction is lost, the 3 novel secondary-site compounds were also no longer able to stimulate secondary conformation responses, suggesting that there is a common TM4 secondary conformation-inducing interaction site. SIGNIFICANCE STATEMENT: The β1-adrenoceptor exists in 2 agonist-stabilized, pharmacologically distinguishable conformations. This study pinpointed the interaction site through which the alternative conformation is stabilized and suggested and evaluated additional ligands, thus providing possible molecular determinants.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"107 11","pages":"100081"},"PeriodicalIF":3.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12799587/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145604609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Both calcium-sensing receptor intracellular C-terminal domains support homodimer signaling.","authors":"Lenah S Binmahfouz, Mahvash A Goolam, Eleanor Barker, Arthur D Conigrave, Donald T Ward","doi":"10.1016/j.molpha.2025.100077","DOIUrl":"10.1016/j.molpha.2025.100077","url":null,"abstract":"<p><p>Extracellular calcium-sensing receptors (CaSRs) are required for whole-body calcium homeostasis and operate as homodimers, shown structurally to bind only one heterotrimeric G protein at a time. Whether the intracellular domain (ICD) of the other, uncoupled monomer is functionally redundant or still required for optimal CaSR signaling remains unknown. Cotransfection of human embryonic kidney 293 cells with receptors containing both extracellular (CaSR₁^S170A) and intracellular (CaSR₂^F801A) mutations, which are nonfunctional when transfected individually, partially rescues function via trans-activation in CaSR₁^S170A:CaSR₂^F801A heterodimers. Further, mutation of an inhibitory, intracellular protein kinase C site T888 permits gain-of-function in CaSR. Therefore, we disabled phosphorylation of this residue (CaSR^T888A) by mutating one, and then both monomers in the CaSR₁^S170A:CaSR₂^F801Atrans-activation-enabled heterodimers. The extracellular Ca²⁺-induced intracellular Ca²⁺ mobilization elicited by CaSR₁^S170A:CaSR₂^F801A was significantly enhanced by disabling one T888 inhibitory phosphorylation site in either CaSR₁^S170A/T888A:CaSR₂^F801A or CaSR₁^S170A:CaSR₂^F801A/T888A, and further enhanced in cells in which both T888 sites had been removed in CaSR₁^S170A/T888A:CaSR₂^F801A/T888A. The results demonstrate that both ICDs of CaSR dimers contribute independently to receptor signaling. Further, in the presence of N-(3-[2-chlorophenyl]propyl)-(R)-alpha-methyl-3-methoxybenzylamine (NPS R-568; CaSR positive allosteric modulator), extracellular Ca²⁺-stimulated signaling from the nonfunctional CaSR^S170A mutant was rescued to wild-type levels by removal of the inhibitory T888 phosphorylation site in CaSR^S170A/T888A homodimers. Therefore, although CaSR^S170A destabilizes the closed (active) form of the Venus fly trap in wild-type homodimers, receptor function can be rescued by relieving intracellular C-terminal domain-dependent inhibition of signaling. SIGNIFICANCE STATEMENT: Despite the homodimeric calcium-sensing receptor coupling to only one G protein at a time, disinhibiting both intracellular domains elicits a greater increase in intracellular Ca²⁺ mobilization than disinhibiting only one, suggesting a positive functional contribution from both subunits.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"107 11","pages":"100077"},"PeriodicalIF":3.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12799464/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145355594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of two structurally diverse positive allosteric modulators on signaling bias at the μ-opioid receptor.","authors":"Mengchu Li, Kelsey E Kochan, M Alexander Stanczyk, Hannah C Stewart, Joshua L West, Andrew D White, Zara Y Weinberg, Manojkumar A Puthenveedu, John R Traynor","doi":"10.1016/j.molpha.2025.100079","DOIUrl":"10.1016/j.molpha.2025.100079","url":null,"abstract":"<p><p>The μ-opioid receptor (MOR) is responsible for the analgesic actions of opioid drugs as well as their unwanted actions, including respiratory depression and addiction liability. Following agonist occupancy, MOR can signal via G-protein and/or β-arrestin. However, MOR agonists may show an imbalance between activating these 2 pathways. Evidence from studies of G-protein-coupled receptors suggests that allosteric modulators can influence agonist signaling profiles. However, no studies have examined this phenomenon at MOR. In this study, we compare the ability of various orthosteric MOR agonists to activate G-protein or recruit β-arrestin in the absence or presence of 2 structurally distinct MOR positive allosteric modulators, BMS-986187 (a xanthenedione) or BMS-986122 (a thiazolidine). We determined the potency and efficacy of 6 orthosteric agonists (DAMGO, fentanyl, methadone, morphine, Met-enkephalin, and SR17018) with and without BMS-986187 or BMS-986122, and determined bias factors for the agonists themselves and in the presence of a modulator. The 2 allosteric modulators enhanced the potency of agonists to different degrees showing probe dependence and differentially shifted the ability of agonists to activate G-protein as compared to recruitment of β-arrestin, indicating an effect on ligand bias. In both measures, in the presence of either modulator, the higher efficacy agonists showed a shift in potency. In contrast, lower efficacy compounds showed an increase in maximal effect with a smaller shift in potency. Overall, the studies provide evidence that positive allosteric modulators influence the degree and direction by which orthosteric agonists signal downstream of MOR. SIGNIFICANCE STATEMENT: Biased agonism and positive allosteric modulation at the μ-opioid receptor have been suggested as approaches to improve the therapeutic index of opioid agonists. This work shows how allosteric modulation alters the bias signaling profile of μ-opioid agonists.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"107 11","pages":"100079"},"PeriodicalIF":3.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13095637/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145378055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Voltage sensor interaction site for a selective small molecule Nav1.1 sodium channel potentiator that enhances firing of fast-spiking interneurons.","authors":"Allison Gallucci, Franck Potet, Sonia Santos, Zhixin Lin, Jonathan Theile, Katrina Yoger, Wenjie Ren, Lingxin Wang, Sylvain Lebreton, Ingrid Attinost, Anil Nair, Armina Omole, Mark Elban, Gareth Young, Jay Spampanato, Neil A Castle","doi":"10.1016/j.molpha.2025.100072","DOIUrl":"10.1016/j.molpha.2025.100072","url":null,"abstract":"<p><p>Nav1.1 voltage-gated sodium (Nav) channels encoded by the SCN1A gene are critical to high frequency action potential generation in inhibitory interneurons and so play a crucial role in maintaining the excitatory-inhibitory balance in the brain. Rare, often loss-of-function, mutations in the SCN1A gene can lead to a spectrum of developmental and epileptic encephalopathies including Dravet syndrome with common SCN1A variants being risk factors for epilepsy, highlighting the potential for Nav1.1 as a therapeutic target for seizure disorders. Here, we describe a potent small molecule sodium channel potentiator ICA00600232 that exhibits >1000-fold selectivity for human Nav1.1 over all other Nav1.x family members except Nav1.3. Nav1.1 potentiation by ICA00600232 results from a slowing of channel inactivation. Employing both chimeras and single point mutations, we demonstrate that ICA00600232 interacts with the domain 4 voltage sensor region of Nav1.1. Three amino acid residues within the \"extracellular\" facing regions of the S2 and S3 transmembrane segments are major determinants of Nav1.1 potentiation and subtype selectivity. These same residues are also important for subtype selective inhibitor interactions with Nav1.1, albeit in a different structural conformation. Furthermore, we demonstrate that ICA00600232 at concentrations as low as 10 nM enhances firing frequency in parvalbumin positive fast-spiking interneurons recorded in brain slices from scn1a^+/- mice. The current study shows that a small molecule Nav1.1 selective potentiator targeting the fourth voltage sensor can slow inactivation of Nav1.1, increase excitability of parvalbumin positive interneurons and inhibitory tone that could be beneficial in treating developmental and epileptic encephalopathies and other seizure disorders. SIGNIFICANCE STATEMENT: Loss-of-function mutations of Nav1.1 sodium channel genes in human inhibitory interneurons are associated with a spectrum of epilepsies including developmental and epileptic encephalopathies. Potential treatments include enhancement of Nav1.1 activity via administration of small molecule potentiating agents. This study describes a potent subtype selective Nav1.1 channel potentiator that interacts with a region that controls voltage sensitivity and enhances action potential firing in inhibitory interneurons, supporting its potential utility in treating developmental and epileptic encephalopathy associated seizure disorders.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"107 10","pages":"100072"},"PeriodicalIF":3.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}