Molecular Pharmacology最新文献

{"title":"Emerging roles of platelet DNA in cancer detection and noninvasive prenatal testing.","authors":"Manli Ding, Xiaohui Huang, Xueqian Ouyang, Fengting Guo, Lanfang Li","doi":"10.1016/j.molpha.2026.100138","DOIUrl":"10.1016/j.molpha.2026.100138","url":null,"abstract":"<p><p>Cell-free DNA (cfDNA) level is a core liquid biopsy biomarker. However, it exhibits low detection sensitivity in early-stage diseases and carries a risk of information loss. Traditionally regarded as anucleate and DNA-deficient, platelets have recently been confirmed to actively take up and carry extracellular DNA-termed platelet DNA (pDNA). We summarized pDNA uptake mechanisms, including clathrin-mediated endocytosis of DNA-loaded extracellular vesicles and direct internalization of free DNA, as well as its pharmacological regulation. Compared with plasma cfDNA levels, pDNA shows superior stability, higher mutant allele frequencies, and resistance to nucleases. We elaborated its clinical potential for early cancer detection by capturing low-abundance tumor mutations and for noninvasive prenatal testing by overcoming the scarcity of fetal cfDNA in early pregnancy. Finally, we discussed integrating pDNA analysis using multiomics and artificial intelligence to advance precision liquid biopsy. SIGNIFICANCE STATEMENT: Platelet DNA level reshapes platelets' role from hemostatic cells to genetic carriers, resolving plasma cell-free DNA level's limitations. It enables early cancer detection and prenatal testing, advancing liquid biopsy toward precision medicine for better diagnostic outcomes.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"108 7","pages":"100138"},"PeriodicalIF":3.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148382373","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":"Where are peptide ligands of potassium channels sourced from?","authors":"Alexey I Kuzmenkov, Alexander A Vassilevski","doi":"10.1016/j.molpha.2026.100135","DOIUrl":"10.1016/j.molpha.2026.100135","url":null,"abstract":"<p><p>Potassium (K⁺) channels are targeted by a wide range of chemical and biological substances, with peptide ligands standing out due to their exceptional affinity and selectivity. Although most of these molecules belong to venom-derived compounds, novel ligands from various less investigated or less popular sources are being discovered. Application of polypeptides is not restricted to fundamental studies and can be expanded to drug discovery, clinical pharmacology, and pharmaceutics. In this report, we offer a concise overview of the diversity of K⁺ channel ligands and their sources, briefly summarizing recent developments in the field and providing an outlook. SIGNIFICANCE STATEMENT: This paper provides a concise overview of the diversity of K⁺ channel ligands and their natural sources, highlights recent advances, and outlines future directions. Although venom-derived polypeptides remain the main source, growing interest is focused on nonvenomous organisms such as plants and mammals. We also discuss artificial polypeptides developed using mutagenesis, and the potential of machine learning and neural networks as promising tools for further molecular design.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"108 7","pages":"100135"},"PeriodicalIF":3.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148405174","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":"Molecular pharmacology of mGlu_7/8 heterodimers reveals unique properties of orthosteric agonists and positive allosteric modulators.","authors":"Anthony S Ferranti, Youhyun Noh, Xia Lei, Xin Lin, Joseph D Bungard, Wesley B Asher, Jonathan A Javitch, Colleen M Niswender","doi":"10.1016/j.molpha.2026.100133","DOIUrl":"10.1016/j.molpha.2026.100133","url":null,"abstract":"<p><p>The metabotropic glutamate (mGlu) receptors are family C G protein-coupled receptors that are widely expressed throughout the central nervous system and function as either homodimers or heterodimers. Recent literature suggests that specific mGlu heterodimer subtypes play critical functional roles in the brain and show unique pharmacological signatures relative to homodimers. We have previously shown that mGlu_7/8 heterodimers may modulate the induction of hippocampal synaptic plasticity using negative allosteric modulators that differentiate between mGlu_7/7 homodimers and mGlu_7/8 heterodimers in vitro. However, we have yet to characterize positive allosteric modulators (PAMs) targeting mGlu₇ and mGlu₈ in a heterodimer-specific assay. Here, we investigated the molecular pharmacology of mGlu_7/8 heterodimers relative to mGlu_7/7 and mGlu_8/8 homodimers using PAMs and various orthosteric agonists using functional assays of controlled receptor activity in HEK293 cells. We demonstrate that an mGlu₈-selective agonist is only active at mGlu_8/8 homodimers and acts as an antagonist at mGlu_7/8 heterodimers. In addition, we show that specific PAMs, such as VU0155094, show greater efficacy at mGlu_7/8 heterodimers in specific assays. Overall, these findings have important implications for the physiological and behavioral roles of mGlu heterodimers and homodimers as it relates to the pharmacology of these compounds. In addition, this study provides a rationale for using a pharmacological toolkit to selectively probe mGlu_7/7, mGlu_8/8, and mGlu_7/8 dimers in native tissues. SIGNIFICANCE STATEMENT: Pharmacological profiling of ligands at mGlu_7/8 heterodimers reveals that this receptor exhibits a unique pharmacological signature relative to mGlu_7/7 and mGlu_8/8 homodimers. This study provides an incentive to investigate the pharmacology of other mGlu heterodimers, screen for heterodimer selective compounds, and use pharmacological tools to investigate the physiological effects of mGlu_7/8 dimers in native tissues.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"108 7","pages":"100133"},"PeriodicalIF":3.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13430957/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148369140","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":"Role of GPR55 in glutamatergic and dopaminergic signaling: A review of preclinical evidence in neuropsychiatric disorders.","authors":"Sanjay N Awathale, Kartik T Nakhate, Noor Ali, Balaji R More, Sameer N Goyal","doi":"10.1016/j.molpha.2026.100131","DOIUrl":"10.1016/j.molpha.2026.100131","url":null,"abstract":"<p><p>G protein-coupled receptor 55 (GPR55) has gained increasing attention for its involvement in various neuropsychiatric disorders. Emerging evidence highlights the critical role of this receptor in modulating brain functions through complex interactions with glutamate and dopamine neurotransmitters. Recent studies suggest that GPR55 is involved in key processes, including synaptic plasticity and reward signaling. Moreover, central GPR55 participated in the pathophysiology of neuropsychiatric conditions such as schizophrenia, depression, anxiety disorders, and addiction. This review aims to provide the current understanding of GPR55, focusing on its molecular and cellular mechanisms, its interactions with glutamatergic and dopaminergic systems, and its potential as a therapeutic target. By exploring the role of GPR55 in regulating neuronal excitability, synaptic dynamics, and brain reward circuitry, we propose GPR55 as a novel and integrative player in the complex network of neurotransmission implicated in neuropsychiatric diseases. Furthermore, we discuss the challenges and opportunities associated with targeting GPR55 for therapeutic intervention in neuropsychiatric conditions that currently have limited therapeutic options. SIGNIFICANCE STATEMENT: This review highlights G protein-coupled receptor 55 (GPR55) as a critical modulator of glutamatergic and dopaminergic signaling, influencing synaptic plasticity and reward processing. Its involvement across multiple neuropsychiatric disorders positions GPR55 as a promising target for developing new therapeutic strategies.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"108 5-6","pages":"100131"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148239582","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":"Ca²⁺/calmodulin-dependent inhibitors of adenylyl cyclase 1 as novel nonopioid analgesics for chronic inflammatory pain.","authors":"Tiffany S Dwyer, Annadka Shrinidhi, Sadikshya Aryal, Martin W Berchtold, Mads Munk, Amanda H Klein, Wendy A Koss, Daniel P Flaherty, Val J Watts","doi":"10.1016/j.molpha.2026.100121","DOIUrl":"10.1016/j.molpha.2026.100121","url":null,"abstract":"<p><p>Adenylyl cyclase 1 (AC1) plays an integral role in the excitatory signaling in the anterior cingulate cortex underlying chronic pain pathophysiology. Upon chronic nociceptive input, sustained Ca²⁺/calmodulin (CaM)-stimulated AC1 activity leads to the development of chronic pain. In this study, we characterize our recently reported series of pyrazolopyrimidinone amine analogs that selectively inhibit Ca²⁺/CaM-stimulated AC1 activity. Lead compounds AC10136A, AC10142A, and AC10172A exhibited potent AC1 inhibition (IC₅₀ = 140-290 nM) and complete selectivity over AC2, AC5, and AC8. All compounds showed high therapeutic indices (>300) and minimal cytotoxicity up to 100 μM. Lead compounds displayed no functional agonism at κ-opioid receptor. Further, compounds prevented and reversed μ-opioid receptor-mediated heterologous sensitization of AC1, highlighting potential utility in mitigating opioid-induced dependence. Further, chronic treatment with lead compounds failed to induce opioid-like adaptations, such as heterologous sensitization, and did not modulate expression of AC1. Mechanistic studies revealed that inhibition is Ca²⁺/CaM dependent but independent of Gα_s, suggesting preferential targeting of the active AC1 conformation. In mice, AC10142A demonstrated analgesic efficacy in the complete Freund adjuvant model of chronic inflammatory pain. Acute and repeated dosing at 48-120 h after complete Freund adjuvant treatment increased mechanical paw withdrawal thresholds and sustained analgesia over this repeated dosing. By targeting Ca²⁺/CaM-bound AC1, these inhibitors preferentially inhibit increased AC1 activity to its normal activity, demonstrating a state-dependent mechanism ideal for chronic pain treatment. Together, these findings establish AC10136A, AC10142A, and AC10172A as potent, selective, and well-tolerated AC1 inhibitors, with promising therapeutic potential for chronic pain and potentially opioid use disorder. SIGNIFICANCE STATEMENT: Adenylyl cyclase 1 (AC1) plays a key role in chronic pain sensitization and opioid use disorder, making it a promising therapeutic target. Selective pyrazolopyrimidinone amine inhibitors of AC1 potently block Ca²⁺/calmodulin-dependent activation (with IC₅₀ values of 140-290 nM), exhibit excellent in vitro safety profiles, prevent μ-opioid receptor-mediated AC1 sensitization in vitro, and demonstrate robust antiallodynic effects in vivo, positioning this compound series as a compelling nonopioid strategy for managing chronic pain and potentially addressing opioid use disorder.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"108 5-6","pages":"100121"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13359510/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147840183","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":"Corrigendum to \"Amantadine derivative Amt-1 enhances antiviral defense against influenza A virus via Nrf2/HO-1 pathway\" [Molecular Pharmacology 108 (2026) 100099].","authors":"Shixin Li, Jingyan Wei, Shaofen Zhou, Shuaiqi Ma, Peihang Jiang, Jian He","doi":"10.1016/j.molpha.2026.100136","DOIUrl":"10.1016/j.molpha.2026.100136","url":null,"abstract":"","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"108 5-6","pages":"100136"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148252417","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":"Identification of potent and selective small molecule TALK-1 inhibitors that promote β-cell function.","authors":"Arya Y Nakhe, Jordyn R Dobson, Prasanna K Dadi, David Westover, Emily L Days, Paige Vinson, C David Weaver, Jerod S Denton, Spencer J Peachee, Soma Behera, Shannon E Gibson, Valentina A Rodriguez Da Silva, Amit Sela, Matthew T Dickerson, David A Jacobson","doi":"10.1016/j.molpha.2026.100130","DOIUrl":"10.1016/j.molpha.2026.100130","url":null,"abstract":"<p><p>The two-pore domain K⁺ (K2P) channel TALK-1 is a key regulator of β-cell electrical excitability, Ca²⁺ handling, and glucose-stimulated insulin secretion. KCNK16, the gene encoding TALK-1, is the most abundant β-cell K⁺ channel transcript and the most islet-restricted ion channel. Genetic evidence also links KCNK16 to diabetic phenotypes, including a gain-of-function polymorphism (rs1535500) that predisposes individuals to type 2 diabetes and a gain-of-function mutation (p.L114P) that causes maturity-onset diabetes of the young. Moreover, ablation of β-cell TALK-1 improves glucose homeostasis in the context of diet-induced obesity. However, it remains unclear if TALK-1 can be pharmacologically targeted to enhance β-cell function and reduce hyperglycemia in type 2 diabetes patients. Here, we identify, to our knowledge, the first selective inhibitors of TALK-1. This was accomplished with a high-throughput fluorescence-based thallium (Tl⁺) flux assay, which identified 286 TALK-1 inhibitors. Of these, 81 compounds selectively inhibited TALK-1 without affecting other K⁺ channels (ie, TALK-2, TASK-3, K_ATP, and hERG). One compound, VU0544194 (K2P16-i7), was selected for further evaluation based on its potency and TALK-1 selectivity. K2P16-i7 inhibited β-cell K2P currents, increased islet Ca²⁺ influx, enhanced endoplasmic reticulum Ca²⁺ storage, and augmented glucose-stimulated insulin secretion. We then identified scaffold domains of K2P16-i7 that, with specific modifications, improved potency while retaining the ability to augment endoplasmic reticulum Ca²⁺ stores. Together, these findings identify, to the best of our knowledge, the first selective small molecule inhibitors of TALK-1 and determine that they improve β-cell function, which could enable an islet-selective therapeutic modality for treating diabetes. SIGNIFICANCE STATEMENT: TALK-1 channels are involved in regulating glucose homeostasis and weight, making them a promising endocrine-specific target for diabetes and obesity. Here, this study identifies, to our knowledge, the first selective TALK-1 inhibitors that show efficacious regulation of islet Ca²⁺ handling and insulin secretion; these molecules will enable future investigation of human endocrine TALK-1 function as well as drug design.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"108 5-6","pages":"100130"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13494105/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148218401","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":"Mechanisms for enhancement of μ-opioid receptor-mediated antinociception in the central nervous system through gallein-dependent modulation of downstream G protein βγ subunit signaling.","authors":"Jacob A Ormes, Alan V Smrcka, Emily M Jutkiewicz","doi":"10.1016/j.molpha.2026.100123","DOIUrl":"10.1016/j.molpha.2026.100123","url":null,"abstract":"<p><p>The clinical utility of μ-opioid receptor (MOR) agonists is limited by side effects and tolerance. G protein βγ subunits (Gβγ) are critical mediators of MOR signaling that not only drive anticonception but also regulate phospholipase C and G protein-coupled receptor kinase pathways that feedback and inhibit MOR signaling. Modulation of Gβγ signaling with small molecules to preferentially inhibit feedback inhibition of MOR has been proposed as a strategy to enhance analgesia without exacerbating adverse effects. In this study, we investigated mechanisms by which gallein, a small-molecule Gβγ signaling modulator, enhances MOR-mediated antinociception in vivo. Gallein pretreatment significantly enhanced the antinociceptive effects of different MOR agonists and nonopioid analgesics that act through Gi-coupled G protein-coupled receptors, with the strongest effects observed upon coadministration with morphine. Gallein-mediated enhancement of morphine-induced antinociception was abolished by the opioid antagonist naloxone and was absent in MOR knockout mice. Notably, systemic naloxone methiodide, which cannot cross the blood-brain barrier, did not prevent gallein-mediated enhancement of morphine-induced antinociception. Intracerebroventricular, but not intrathecal, administration of gallein enhanced morphine-induced antinociception. Gallein was also effective at enhancing the action of morphine in a hot plate assay, implicating supraspinal MOR dependency. Lastly, 10 S/T-A mice expressing phosphosite-deficient MORs lost responsiveness to gallein treatment, supporting a mechanism of action in which gallein inhibits Gβγ-dependent inhibitory feedback phosphorylation of MOR in the central nervous system. SIGNIFICANCE STATEMENT: These findings provide insight into the mechanisms for potentiation of the antinociceptive effects of μ-opioid receptor (MOR) agonists via modulation of G protein βγ (Gβγ) signaling pathways. The study demonstrates dependence on central MORs and requires the ability of MOR to be feedback-regulated through phosphorylation. Pharmacological modulation of Gβγ signaling could serve as effective adjuncts to traditional opioid therapy.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"108 5-6","pages":"100123"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13494096/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147973797","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":"Local protein kinase A signaling pathologies in the endocrine system.","authors":"Kristan H Cleveland, John D Scott","doi":"10.1016/j.molpha.2026.100128","DOIUrl":"10.1016/j.molpha.2026.100128","url":null,"abstract":"<p><p>Endocrine signaling relies heavily on the second messenger cAMP to influence different functional outcomes including hormone secretion, steroidogenesis, ion channel regulation, and cell growth. Selectivity of cAMP action is often achieved through compartmentalized activation of protein kinase A (PKA). Local PKA action is organized by A-kinase anchoring proteins. These organellar enzyme scaffolds not only define where and when PKA phosphorylation occurs but also influence which substrates are accessible. A substantial literature suggests that endocrine disease can arise from lesions that promote dysfunctional PKA signaling. Recent studies suggests that common PKA mutations disrupt localization, causing the mutant catalytic subunits to escape A-kinase anchoring protein complexes. Such pathological events are evident in endocrine disorders such as Carney complex, sporadic primary pigmented nodular adrenocortical disease, and adrenal Cushing syndrome where somatic mutations in PKA subunits uncouple normal spatial control of the kinase. We postulate that future therapies should aim to restore the fidelity of local PKA signaling. SIGNIFICANCE STATEMENT: Compartmentalized cAMP signaling, organized by A-kinase anchoring protein scaffolds, is essential for ensuring precise spatial and functional control of endocrine processes. Disruption of this localization by disease-associated protein kinase A mutations uncouples signaling fidelity and drives endocrine pathologies, highlighting restoration of localized protein kinase A activity as a promising therapeutic strategy.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"108 5-6","pages":"100128"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13632512/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148163673","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":"G protein-coupled receptor kinase 3 couples atypical chemokine receptor 4 independent of G proteins.","authors":"Thomas D Lamme, Isabel B Sánchez Arroyo, Martine J Smit, Christopher T Schafer","doi":"10.1016/j.molpha.2026.100129","DOIUrl":"10.1016/j.molpha.2026.100129","url":null,"abstract":"<p><p>Atypical chemokine receptors (ACKRs) indirectly mediate cell migration through chemokine scavenging, which generally requires phosphorylation by G protein-coupled receptor kinases (GRKs) to efficiently control chemokine levels. Despite not coupling to G proteins, ACKR4 is preferentially modified by GRK3, a kinase dependent on active G protein subunits for membrane translocation and phosphorylation activity. How ACKR4 circumvents G protein dependency to engage GRK3 is unclear. To resolve the underlying mechanism, we used live-cell bioluminescence resonance energy transfer assays to measure GRK3 and phosphorylation-dependent arrestin recruitment and tracked the impact of fluorescent chemokine uptake by flow cytometry. We demonstrate that ACKR4 engages arrestin preferentially downstream of GRK2/3 phosphorylation fully independent of G protein coordination. Instead, the kinases are recruited directly to the atypical receptor via a unique acidic-rich motif in the proximal receptor C terminus. Mutations in this region severely impaired kinase and arrestin recruitment, as well as chemokine scavenging. Productive phosphorylation also plays a substantial role in G protein-independent GRK3 translocation to ACKR4, and recruitment of kinase-dead GRK3 is severely impaired. Together, these findings suggest that ACKR4 directly coordinates GRK3 coupling, highlighting a uniquely evolved atypical mechanism to use GRK2/3 while bypassing G protein activation and thereby supporting efficient chemokine scavenging by the atypical receptor. SIGNIFICANCE STATEMENT: Cell migration and positioning is efficiently regulated by atypical chemokine receptors (ACKR) through chemokine scavenging, often upon GRK phosphorylation. GRK3 dominates the phosphorylation of ACKR4, despite ACKR4 not activating G proteins needed to promote the kinase activity. This study resolved that ACKR4 is directly modified by GRK3 without G protein involvement. Instead, specific acidic residues coordinate the phosphorylation reaction. While seemingly unique to ACKR4, similar mechanisms for GRK2/3 action may contribute to kinase modification of other atypical and canonical GPCRs.</p>","PeriodicalId":18767,"journal":{"name":"Molecular Pharmacology","volume":"108 5-6","pages":"100129"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13494237/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148239632","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}