RESUMO
Small molecule neurotensin receptor 1 (NTSR1) agonists have been pursued for more than 40 years as potential therapeutics for psychiatric disorders, including drug addiction. Clinical development of NTSR1 agonists has, however, been precluded by their severe side effects. NTSR1, a G protein-coupled receptor (GPCR), signals through the canonical activation of G proteins and engages ß-arrestins to mediate distinct cellular signaling events. Here, we characterize the allosteric NTSR1 modulator SBI-553. This small molecule not only acts as a ß-arrestin-biased agonist but also extends profound ß-arrestin bias to the endogenous ligand by selectively antagonizing G protein signaling. SBI-553 shows efficacy in animal models of psychostimulant abuse, including cocaine self-administration, without the side effects characteristic of balanced NTSR1 agonism. These findings indicate that NTSR1 G protein and ß-arrestin activation produce discrete and separable physiological effects, thus providing a strategy to develop safer GPCR-targeting therapeutics with more directed pharmacological action.
Assuntos
Comportamento Aditivo/metabolismo , Receptores de Neurotensina/metabolismo , beta-Arrestinas/metabolismo , Regulação Alostérica/efeitos dos fármacos , Regulação Alostérica/fisiologia , Animais , Comportamento Aditivo/tratamento farmacológico , Linhagem Celular , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Bibliotecas de Moléculas Pequenas/farmacologiaRESUMO
The pancreatic hormone glucagon activates the glucagon receptor (GCGR), a class B seven-transmembrane G protein-coupled receptor that couples to the stimulatory heterotrimeric G protein and provokes PKA-dependent signaling cascades vital to hepatic glucose metabolism and islet insulin secretion. Glucagon-stimulation also initiates recruitment of the endocytic adaptors, ßarrestin1 and ßarrestin2, which regulate desensitization and internalization of the GCGR. Unlike many other G protein-coupled receptors, the GCGR expressed at the plasma membrane is constitutively ubiquitinated and upon agonist-activation, internalized GCGRs are deubiquitinated at early endosomes and recycled via Rab4-containing vesicles. Herein we report a novel link between the ubiquitination status and signal transduction mechanism of the GCGR. In the deubiquitinated state, coupling of the GCGR to Gs is diminished, while binding to ßarrestin is enhanced with signaling biased to a ßarrestin1-dependent p38 mitogen activated protein kinase (MAPK) pathway. This ubiquitin-dependent signaling bias arises through the modification of lysine333 (K333) on the cytoplasmic face of transmembrane helix V. Compared with the GCGR-WT, the mutant GCGR-K333R has impaired ubiquitination, diminished G protein coupling, and PKA signaling but unimpaired potentiation of glucose-stimulated-insulin secretion in response to agonist-stimulation, which involves p38 MAPK signaling. Both WT and GCGR-K333R promote the formation of glucagon-induced ßarrestin1-dependent p38 signaling scaffold that requires canonical upstream MAPK-Kinase3, but is independent of Gs, Gi, and ßarrestin2. Thus, ubiquitination/deubiquitination at K333 in the GCGR defines the activation of distinct transducers with the potential to influence various facets of glucagon signaling in health and disease.
Assuntos
Glucagon , Receptores de Glucagon , Ubiquitinação , Glucagon/metabolismo , Glucose/metabolismo , Fígado/metabolismo , Receptores de Glucagon/genética , Receptores de Glucagon/metabolismo , Humanos , Células HEK293RESUMO
Arrestins and their yeast homologs, arrestin-related trafficking adaptors (ARTs), share a stretch of 29 amino acids called the ART motif. However, the functionality of that motif is unknown. We now report that deleting this motif prevents agonist-induced ubiquitination of ß-arrestin2 (ß-arr2) and blocks its association with activated G protein-coupled receptors (GPCRs). Within the ART motif, we have identified a conserved phenylalanine residue, Phe116, that is critical for the formation of ß-arr2-GPCR complexes. ß-arr2 Phe116Ala mutant has negligible effect on blunting ß2-adrenergic receptor-induced cAMP generation unlike ß-arr2, which promotes rapid desensitization. Furthermore, available structures for inactive and inositol hexakisphosphate 6-activated forms of bovine ß-arr2 revealed that Phe116 is ensconced in a hydrophobic pocket, whereas the adjacent Phe117 and Phe118 residues are not. Mutagenesis of Phe117 and Phe118, but not Phe116, preserves GPCR interaction of ß-arr2. Surprisingly, Phe116 is dispensable for the association of ß-arr2 with its non-GPCR partners. ß-arr2 Phe116Ala mutant presents a significantly reduced protein half-life compared with ß-arr2 and undergoes constitutive Lys-48-linked polyubiquitination, which tags proteins for proteasomal degradation. We also found that Phe116 is critical for agonist-dependent ß-arr2 ubiquitination with Lys-63-polyubiquitin linkages that are known mediators of protein scaffolding and signal transduction. Finally, we have shown that ß-arr2 Phe116Ala interaction with activated ß2-adrenergic receptor can be rescued with an in-frame fusion of ubiquitin. Taken together, we conclude that Phe116 preserves structural stability of ß-arr2, regulates the formation of ß-arr2-GPCR complexes that inhibit G protein signaling, and promotes subsequent ubiquitin-dependent ß-arr2 localization and trafficking.
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Fenilalanina , Receptores Acoplados a Proteínas G/metabolismo , beta-Arrestina 2 , Animais , Bovinos , Ubiquitina/metabolismo , beta-Arrestina 2/química , beta-Arrestina 2/genética , beta-Arrestina 2/metabolismoRESUMO
BACKGROUND: Deafness, autosomal recessive 16 (DFNB16) is caused by compound heterozygous or homozygous variants in STRC and is the second most common form of genetic hearing loss. Due to the nearly identical sequences of STRC and the pseudogene STRCP1, analysis of this region is challenging in clinical testing. METHODS: We developed a method that accurately identifies the copy number of STRC and STRCP1 using standard short-read genome sequencing. Then, we used whole genome sequencing (WGS) data to investigate the population distribution of STRC copy number in 6813 neonates and the correlation between STRC and STRCP1 copy number. RESULTS: The comparison of WGS results with multiplex ligation-dependent probe amplification demonstrated high sensitivity (100%; 95% CI, 97.5%-100%) and specificity (98.8%; 95% CI, 97.7%-99.5%) in detecting heterozygous deletion of STRC from short-read genome sequencing data. The population analysis revealed that 5.22% of the general population has STRC copy number changes, almost half of which (2.33%; 95% CI, 1.99%-2.72%) were clinically significant, including heterozygous and homozygous STRC deletions. There was a strong inverse correlation between STRC and STRCP1 copy number. CONCLUSIONS: We developed a novel and reliable method to determine STRC copy number based on standard short-read based WGS data. Incorporating this method into analytic pipelines would improve the clinical utility of WGS in the screening and diagnosis of hearing loss. Finally, we provide population-based evidence of pseudogene-mediated gene conversions between STRC and STRCP1.
Assuntos
Perda Auditiva Neurossensorial , Perda Auditiva , Recém-Nascido , Humanos , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/genética , Perda Auditiva/diagnóstico , Perda Auditiva/genética , Sequência de Bases , Homozigoto , Variações do Número de Cópias de DNA , Peptídeos e Proteínas de Sinalização Intercelular/genéticaRESUMO
As the hardest tissue formed by vertebrates, enamel represents nature's engineering masterpiece with complex organizations of fibrous apatite crystals at the nanometer scale. Supramolecular assemblies of enamel matrix proteins (EMPs) play a key role as the structural scaffolds for regulating mineral morphology during enamel development. However, to achieve maximum tissue hardness, most organic content in enamel is digested and removed at the maturation stage, and thus knowledge of a structural protein template that could guide enamel mineralization is limited at this date. Herein, by examining a gene-modified mouse that lacked enzymatic degradation of EMPs, we demonstrate the presence of protein nanoribbons as the structural scaffolds in developing enamel matrix. Using in vitro mineralization assays we showed that both recombinant and enamel-tissue-based amelogenin nanoribbons are capable of guiding fibrous apatite nanocrystal formation. In accordance with our understanding of the natural process of enamel formation, templated crystal growth was achieved by interaction of amelogenin scaffolds with acidic macromolecules that facilitate the formation of an amorphous calcium phosphate precursor which gradually transforms into oriented apatite fibers along the protein nanoribbons. Furthermore, this study elucidated that matrix metalloproteinase-20 is a critical regulator of the enamel mineralization as only a recombinant analog of a MMP20-cleavage product of amelogenin was capable of guiding apatite mineralization. This study highlights that supramolecular assembly of the scaffold protein, its enzymatic processing, and its ability to interact with acidic carrier proteins are critical steps for proper enamel development.
Assuntos
Amelogenina/química , Esmalte Dentário/metabolismo , Amelogênese , Amelogenina/metabolismo , Animais , Apatitas/química , Apatitas/metabolismo , Esmalte Dentário/química , Proteínas do Esmalte Dentário/química , Proteínas do Esmalte Dentário/metabolismo , Camundongos , Nanofibras/químicaRESUMO
OBJECTIVE: To identify and describe in-session interaction patterns between psychoanalytic therapists and adolescents diagnosed with major depressive disorder, comparing good and poor outcome cases. METHOD: Audio recordings for 100 psychotherapy sessions from 10 Short-Term Psychoanalytic Psychotherapies were analysed using the Adolescent Psychotherapy Q-Set (APQ). The cases and sessions were evenly divided into two groups (poor outcome and good outcome, 5 patients and 50 sessions per group). Interaction patterns were analysed with an Exploratory Factor Analysis (EFA), while group differences were assessed through t-tests. RESULTS: The EFA revealed three factors: (1) "Open, engaged young person working collaboratively with a therapist to make sense of their experiences", (2) "Directive therapist with a young person fluctuating in emotional state and unwilling to explore", (3) "Young person expressing anger and irritation and challenging the therapist". Factor 1 was significantly more prominent in the good outcome cases, while factor 3, on the contrary, was more significantly related to the poor outcome cases. Factor 2 was equally present in both groups. CONCLUSION: Besides reinforcing to researchers and clinicians the association between a collaborative psychotherapy process with good outcomes, our findings also provide empirical data regarding the role of anger in adolescent depression and the psychotherapy process.
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Synthetic and materials chemistry initiatives have enabled the translation of the macromolecular functions of biology into synthetic frameworks. These explorations into alternative chemistries of life attempt to capture the versatile functionality and adaptability of biopolymers in new orthogonal scaffolds. Information storage and transfer, however, so beautifully represented in the central dogma of biology, require multiple components functioning synergistically. Over a single decade, the emerging field of systems chemistry has begun to catalyze the construction of mutualistic biopolymer networks, and this review begins with the foundational small-molecule-based dynamic chemical networks and peptide amyloid-based dynamic physical networks on which this effort builds. The approach both contextualizes the versatile approaches that have been developed to enrich chemical information in synthetic networks and highlights the properties of amyloids as potential alternative genetic elements. The successful integration of both chemical and physical networks through ß-sheet assisted replication processes further informs the synergistic potential of these networks. Inspired by the cooperative synergies of nucleic acids and proteins in biology, synthetic nucleic-acid-peptide chimeras are now being explored to extend their informational content. With our growing range of synthetic capabilities, structural analyses, and simulation technologies, this foundation is radically extending the structural space that might cross the Darwinian threshold for the origins of life as well as creating an array of alternative systems capable of achieving the progressive growth of novel informational materials.
Assuntos
Biopolímeros/química , Ácidos Nucleicos/química , Peptídeos/química , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Biopolímeros/metabolismo , Nanotubos/química , Ácidos Nucleicos/metabolismo , Ácidos Nucleicos Peptídicos/química , Ácidos Nucleicos Peptídicos/metabolismo , Peptídeos/metabolismo , Ribonucleoproteínas/química , Ribonucleoproteínas/metabolismoRESUMO
Correction for 'Achieving biopolymer synergy in systems chemistry' by Yushi Bai et al., Chem. Soc. Rev., 2018, DOI: 10.1039/c8cs00174j.
RESUMO
Apelin signaling plays an important role during embryo development and regulates angiogenesis, cardiovascular activity, and energy metabolism in adulthood. Overexpression and hyperactivity of this signaling pathway is observed in various pathologic states, such as cardiovascular diseases and cancer, which highlights the importance of inhibiting apelin receptor (APJ); therefore, we developed a cell-based screening assay that uses fluorescence microscopy to identify APJ antagonists. This approach led us to identify the U.S. Food and Drug Administration-approved compound protamine-already used clinically after cardiac surgery-as an agent to bind to heparin and thereby reverse its anticlotting activity. Protamine displays a 390-nM affinity for APJ and behaves as a full antagonist with regard to G protein and ß-arrestin-dependent intracellular signaling. Ex vivo and in vivo, protamine abolishes well-known apelin effects, such as angiogenesis, glucose tolerance, and vasodilatation. Remarkably, protamine antagonist activity is fully reversed by heparin treatment both in vitro and in vivo Thus, our results demonstrate a new pharmacologic property of protamine-blockade of APJ-that could explain some adverse effects observed in protamine-treated patients. Moreover, our data reveal that the established antiangiogenic activity of protamine would rely on APJ antagonism.-Le Gonidec, S., Chaves-Almagro, C., Bai, Y., Kang, H. J., Smith, A., Wanecq, E., Huang, X.-P., Prats, H., Knibiehler, B., Roth, B. L., Barak, L. S., Caron, M. G., Valet, P., Audigier, Y., Masri, B. Protamine is an antagonist of apelin receptor, and its activity is reversed by heparin.
Assuntos
Heparina/farmacologia , Protaminas/farmacologia , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Animais , Receptores de Apelina , Linhagem Celular Tumoral , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismoRESUMO
Nature endows life with a wide variety of sophisticated, synergistic, and highly functional protein assemblies. Following Nature's inspiration to assemble protein building blocks into exquisite nanostructures is emerging as a fascinating research field. Dictating protein assembly to obtain highly ordered nanostructures and sophisticated functions not only provides a powerful tool to understand the natural protein assembly process but also offers access to advanced biomaterials. Over the past couple of decades, the field of protein assembly has undergone unexpected and rapid developments, and various innovative strategies have been proposed. This Review outlines recent advances in the field of protein assembly and summarizes several strategies, including biotechnological strategies, chemical strategies, and combinations of these approaches, for manipulating proteins to self-assemble into desired nanostructures. The emergent applications of protein assemblies as versatile platforms to design a wide variety of attractive functional materials with improved performances have also been discussed. The goal of this Review is to highlight the importance of this highly interdisciplinary field and to promote its growth in a diverse variety of research fields ranging from nanoscience and material science to synthetic biology.
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Técnicas de Química Sintética/métodos , Nanoestruturas/química , Multimerização Proteica , Proteínas/química , Simulação por Computador , DNA/química , Ligantes , Substâncias Macromoleculares/química , Estrutura Quaternária de ProteínaRESUMO
The pseudostratified airway epithelium of the lung contains a balanced proportion of multiciliated and secretory luminal cells that are maintained and regenerated by a population of basal stem cells. However, little is known about how these processes are modulated in vivo, and about the potential role of cytokine signaling between stem and progenitor cells and their niche. Using a clonal 3D organoid assay, we found that IL-6 stimulated, and Stat3 inhibitors reduced, the generation of ciliated vs. secretory cells from basal cells. Gain-of-function and loss-of-function studies with cultured mouse and human basal cells suggest that IL-6/Stat3 signaling promotes ciliogenesis at multiple levels, including increases in multicilin gene and forkhead box protein J1 expression and inhibition of the Notch pathway. To test the role of IL-6 in vivo genetically, we followed the regeneration of mouse tracheal epithelium after ablation of luminal cells by inhaled SO2. Stat3 is activated in basal cells and their daughters early in the repair process, correlating with an increase in Il-6 expression in platelet-derived growth factor receptor alpha(+) mesenchymal cells in the stroma. Conditional deletion in basal cells of suppressor of cytokine signaling 3, encoding a negative regulator of the Stat3 pathway, results in an increase in multiciliated cells at the expense of secretory and basal cells. By contrast, Il-6 null mice regenerate fewer ciliated cells and an increased number of secretory cells after injury. The results support a model in which IL-6, produced in the reparative niche, functions to enhance the differentiation of basal cells, and thereby acts as a "friend" to promote airway repair rather than a "foe."
Assuntos
Interleucina-6/metabolismo , Mucosa Respiratória/citologia , Fator de Transcrição STAT3/metabolismo , Animais , Brônquios/citologia , Diferenciação Celular/fisiologia , Cílios/fisiologia , Modelos Animais de Doenças , Células Epiteliais/citologia , Células Epiteliais/fisiologia , Proteínas de Fluorescência Verde/genética , Humanos , Interleucina-6/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosforilação/fisiologia , Cultura Primária de Células , Regeneração/fisiologia , Mucosa Respiratória/fisiologia , Fator de Transcrição STAT3/genética , Transdução de Sinais/fisiologia , Células-Tronco/citologia , Células-Tronco/fisiologia , Traqueia/citologiaRESUMO
Proteins, as the elemental basis of living organisms, mostly execute their biological tasks in the form of supramolecular self-assemblies with subtle architectures, dynamic interactions and versatile functionalities. Inspired by the structural harmony and functional beauty of natural protein self-assemblies to fabricate sophisticated yet highly ordered protein superstructures represents an adventure in the pursuit of nature's supreme wisdom. In this review, we focus on building protein self-assembly systems based on supramolecular strategies and classify recent progress by the types of utilized supramolecular driving forces. Especially, the design strategy, structure control and the thermodynamic/kinetic regulation of the self-assemblies, which will in turn provide insights into the natural biological self-assembly mechanism, are highlighted. In addition, recently, this research field is starting to extend its interest beyond constructing complex morphologies towards the potential applications of the self-assembly systems; several attempts to design functional protein complexes are also discussed. As such, we hope that this review will provide a panoramic sketch of the field and draw a roadmap towards the ultimate construction of advanced protein self-assemblies that even can serve as analogues of their natural counterparts.
Assuntos
Substâncias Macromoleculares/química , Nanoestruturas/química , Multimerização Proteica , Estrutura Quaternária de Proteína , Proteínas/química , Cinética , Modelos Químicos , Conformação Proteica , TermodinâmicaRESUMO
BACKGROUND: Membrane proteins regulate a diversity of physiological processes and are the most successful class of targets in drug discovery. However, the number of targets adequately explored in chemical space and the limited resources available for screening are significant problems shared by drug-discovery centers and small laboratories. Therefore, a low-cost and universally applicable screen for membrane protein trafficking was developed. RESULTS: This high-throughput screen (HTS), termed IRFAP-HTS, utilizes the recently described MarsCy1-fluorogen activating protein and the near-infrared and membrane impermeant fluorogen SCi1. The cell surface expression of MarsCy1 epitope-tagged receptors can be visualized by simple addition of SCi1. User-friendly, rapid, and quantitative detection occurs on a standard infrared western-blotting scanner. The reliability and robustness of IRFAP-HTS was validated by confirming human vasopressin-2 receptor and dopamine receptor-2 trafficking in response to agonist or antagonist. The IRFAP-HTS screen was deployed against the leucine-rich G protein-coupled receptor-5 (Lgr5). Lgr5 is expressed in stem cells, modulates Wnt/ß-catenin signaling, and is therefore a promising drug target. However, small molecule modulators have yet to be reported. The constitutive internalization of Lgr5 appears to be one primary mode through which its function is regulated. Therefore, IRFAP-HTS was utilized to screen 11,258 FDA-approved and drug-like small molecules for those that antagonize Lgr5 internalization. Glucocorticoids were found to potently increase Lgr5 expression at the plasma membrane. CONCLUSION: The IRFAP-HTS platform provides a versatile solution for screening more targets with fewer resources. Using only a standard western-blotting scanner, we were able to screen 5,000 compounds per hour in a robust and quantitative assay. Multi-purposing standardly available laboratory equipment eliminates the need for idiosyncratic and more expensive high-content imaging systems. The modular and user-friendly IRFAP-HTS is a significant departure from current screening platforms. Small laboratories will have unprecedented access to a robust and reliable screening platform and will no longer be limited by the esoteric nature of assay development, data acquisition, and post-screening analysis. The discovery of glucocorticoids as modulators for Lgr5 trafficking confirms that IRFAP-HTS can accelerate drug-discovery and drug-repurposing for even the most obscure targets.
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Descoberta de Drogas/métodos , Ensaios de Triagem em Larga Escala/métodos , Proteínas de Membrana/metabolismo , Descoberta de Drogas/economia , Células HEK293 , Ensaios de Triagem em Larga Escala/economia , Humanos , Transporte Proteico , Reprodutibilidade dos TestesRESUMO
The G protein-coupled ghrelin receptor GHSR1a is a potential pharmacological target for treating obesity and addiction because of the critical role ghrelin plays in energy homeostasis and dopamine-dependent reward. GHSR1a enhances growth hormone release, appetite, and dopamine signaling through G(q/11), G(i/o), and G(12/13) as well as ß-arrestin-based scaffolds. However, the contribution of individual G protein and ß-arrestin pathways to the diverse physiological responses mediated by ghrelin remains unknown. To characterize whether a signaling bias occurs for GHSR1a, we investigated ghrelin signaling in a number of cell-based assays, including Ca(2+) mobilization, serum response factor response element, stress fiber formation, ERK1/2 phosphorylation, and ß-arrestin translocation, utilizing intracellular second loop and C-tail mutants of GHSR1a. We observed that GHSR1a and ß-arrestin rapidly form metastable plasma membrane complexes following exposure to an agonist, but replacement of the GHSR1a C-tail by the tail of the vasopressin 2 receptor greatly stabilizes them, producing complexes observable on the plasma membrane and also in endocytic vesicles. Mutations of the contiguous conserved amino acids Pro-148 and Leu-149 in the GHSR1a intracellular second loop generate receptors with a strong bias to G protein and ß-arrestin, respectively, supporting a role for conformation-dependent signaling bias in the wild-type receptor. Our results demonstrate more balance in GHSR1a-mediated ERK signaling from G proteins and ß-arrestin but uncover an important role for ß-arrestin in RhoA activation and stress fiber formation. These findings suggest an avenue for modulating drug abuse-associated changes in synaptic plasticity via GHSR1a and indicate the development of GHSR1a-biased ligands as a promising strategy for selectively targeting downstream signaling events.
Assuntos
Arrestina/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Receptores de Grelina/metabolismo , Arrestina/genética , Proteínas de Ligação ao GTP/genética , Células HEK293 , Humanos , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Plasticidade Neuronal/fisiologia , Estabilidade Proteica , Estrutura Secundária de Proteína , Transporte Proteico/fisiologia , Receptores de Grelina/genética , Receptores de Vasopressinas/genética , Receptores de Vasopressinas/metabolismoRESUMO
ß-Arrestins regulate G protein-coupled receptor signaling as competitive inhibitors and protein adaptors. Low molecular weight biased ligands that bind receptors and discriminate between the G protein dependent arm and ß-arrestin, clathrin-associated arm of receptor signaling are considered therapeutically valuable as a result of this distinctive pharmacological behavior. Other than receptor agonists, compounds that activate ß-arrestins are not available. We show that within minutes of exposure to the cationic triphenylmethane dyes malachite green and brilliant green, tissue culture cells recruit ß-arrestins to clathrin scaffolds in a receptor-activation independent manner. In the presence of these compounds, G protein signaling is inhibited, ERK and GSK3ß signaling are preserved, and the recruitment of the beta2-adaptin, AP2 adaptor complex to clathrin as well as transferrin internalization is reduced. Moreover, malachite green binds ß-arrestin2-GFP coated immunotrap beads relative to GFP only coated beads. Triphenylmethane dyes are FDA approved for topical use on newborns as components of triple-dye preparations and are not approved but used effectively as aqueous antibiotics in fish husbandry. As possible carcinogens, their chronic ingestion in food preparations, particularly through farmed fish, is discouraged in the U.S. and Europe. Our results indicate triphenylmethane dyes as a result of novel pharmacology may have additional roles as ß-arrestin/clathrin pathway signaling modulators in both pharmacology research and clinical therapy.
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Arrestinas/metabolismo , Compostos de Amônio Quaternário/metabolismo , Corantes de Rosanilina/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Corantes , Endocitose , Proteínas de Ligação ao GTP/metabolismo , Células HEK293 , Humanos , Compostos de Amônio Quaternário/química , Receptores de Neurotensina/química , Receptores de Neurotensina/metabolismo , Corantes de Rosanilina/química , Transdução de Sinais , beta-ArrestinasRESUMO
GPR55 is a class A G protein-coupled receptor (GPCR) that has been implicated in inflammatory pain, neuropathic pain, metabolic disorder, bone development, and cancer. Initially deorphanized as a cannabinoid receptor, GPR55 has been shown to be activated by non-cannabinoid ligands such as l-α-lysophosphatidylinositol (LPI). While there is a growing body of evidence of physiological and pathophysiological roles for GPR55, the paucity of specific antagonists has limited its study. In collaboration with the Molecular Libraries Probe Production Centers Network initiative, we identified a series of GPR55 antagonists using a ß-arrestin, high-throughput, high-content screen of ~300000 compounds. This screen yielded novel, GPR55 antagonist chemotypes with IC50 values in the range of 0.16-2.72 µM [Heynen-Genel, S., et al. (2010) Screening for Selective Ligands for GPR55: Antagonists (ML191, ML192, ML193) (Bookshelf ID NBK66153; PMID entry 22091481)]. Importantly, many of the GPR55 antagonists were completely selective, with no agonism or antagonism against GPR35, CB1, or CB2 up to 20 µM. Using a model of the GPR55 inactive state, we studied the binding of an antagonist series that emerged from this screen. These studies suggest that GPR55 antagonists possess a head region that occupies a horizontal binding pocket extending into the extracellular loop region, a central ligand portion that fits vertically in the receptor binding pocket and terminates with a pendant aromatic or heterocyclic ring that juts out. Both the region that extends extracellularly and the pendant ring are features associated with antagonism. Taken together, our results provide a set of design rules for the development of second-generation GPR55 selective antagonists.
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Avaliação Pré-Clínica de Medicamentos , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/química , Sítios de Ligação , Humanos , Concentração Inibidora 50 , Ligantes , Modelos Moleculares , Ligação Proteica , Receptores de Canabinoides , Receptores Acoplados a Proteínas G/metabolismoRESUMO
Protein self-assembly into exquisite, complex, yet highly ordered architectures represents the supreme wisdom of nature. However, precise manipulation of protein self-assembly behavior in vitro is a great challenge. Here we report that by taking advantage of the cooperation of metal-ion-chelating interactions and nonspecific protein-protein interactions, we achieved accurate control of the orientation of proteins and their self-assembly into protein nanorings. As a building block, we utilized the C2-symmetric protein sjGST-2His, a variant of glutathione S-transferase from Schistosoma japonicum having two properly oriented His metal-chelating sites on the surface. Through synergic metal-coordination and non-covalent interactions, sjGST-2His self-assembled in a fixed bending manner to form highly ordered protein nanorings. The diameters of the nanorings can be regulated by tuning the strength of the non-covalent interaction network between sjGST-2His interfaces through variation of the ionic strength of the solution. This work provides a de novo design strategy that can be applied in the construction of novel protein superstructures.
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Desenho de Fármacos , Glutationa Transferase/química , Nanoestruturas/química , Multimerização Proteica , Animais , Quelantes/química , Estrutura Quaternária de Proteína , Schistosoma japonicum/enzimologiaRESUMO
By combining computational design and site-directed mutagenesis, we have engineered a new catalytic ability into the antibody scFv2F3 by installing a catalytic triad (Trp(29)-Sec(52)-Gln(72)). The resulting abzyme, Se-scFv2F3, exhibits a high glutathione peroxidase (GPx) activity, approaching the native enzyme activity. Activity assays and a systematic computational study were performed to investigate the effect of successive replacement of residues at positions 29, 52, and 72. The results revealed that an active site Ser(52)/Sec substitution is critical for the GPx activity of Se-scFv2F3. In addition, Phe(29)/Trp-Val(72)/Gln mutations enhance the reaction rate via functional cooperation with Sec(52). Molecular dynamics simulations showed that the designed catalytic triad is very stable and the conformational flexibility caused by Tyr(101) occurs mainly in the loop of complementarity determining region 3. The docking studies illustrated the importance of this loop that favors the conformational shift of Tyr(54), Asn(55), and Gly(56) to stabilize substrate binding. Molecular dynamics free energy and molecular mechanics-Poisson Boltzmann surface area calculations estimated the pK(a) shifts of the catalytic residue and the binding free energies of docked complexes, suggesting that dipole-dipole interactions among Trp(29)-Sec(52)-Gln(72) lead to the change of free energy that promotes the residual catalytic activity and the substrate-binding capacity. The calculated results agree well with the experimental data, which should help to clarify why Se-scFv2F3 exhibits high catalytic efficiency.
Assuntos
Glutationa Peroxidase/química , Glutationa Peroxidase/metabolismo , Mutação , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/metabolismo , Sequência de Aminoácidos , Anticorpos Catalíticos/química , Anticorpos Catalíticos/genética , Anticorpos Catalíticos/metabolismo , Domínio Catalítico , Glutationa Peroxidase/genética , Cinética , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Anticorpos de Cadeia Única/genética , TermodinâmicaRESUMO
[This corrects the article DOI: 10.3389/fphys.2022.1063970.].
RESUMO
Importance: Adversity during childhood can limit children's chances of achieving their optimal developmental and psychological outcomes. Well-designed observational studies might help identify adversities that are most implicated in this, thereby helping to identify potential targets for developing interventions. Objective: To compare the association between preventing childhood poverty, parental mental illness and parental separation, and the population rate of offspring common mental disorders (ages 16-21 years) or average school grades (age 16 years). Design, Setting, and Participants: A population-based, longitudinal cohort study using Swedish registries was conducted. A total of 163â¯529 children born in Sweden between January 1, 1996, and December 31, 1997, were followed up until their 21st birthday. They were linked to registries using Sweden's national personal identification number. Children were linked to birth parents, hospital records, and school data. Parents were linked to registries containing health, income, sociodemographic, and obstetric data. Analyses were conducted between January 10, 2021, and August 26, 2022. Exposures: Childhood adversities of relative poverty (household disposable income <50% of the median), parental inpatient admission for a mental illness, or parental separation. Adversities were categorized into developmental periods: ages 0 to 3, 4 to 7, 8 to 11, and 12 to 16 years. Main Outcomes and Measures: The main outcomes were children's hospital records with a diagnosis of anxiety or depression between ages 16 and 21 years and school grades at the end of compulsory education (age 16 years). The parametric g-formula modeled population changes in outcomes associated with the counterfactual, hypothetical preventing adversity exposures, accounting for fixed and time-varying confounders. Adjustments were made for parental demographic characteristics, obstetric variables, and socioeconomic data at birth. Results: A total of 163â¯529 children were included in the cohort (51.2% boys, 51.4% born in 1996). Preventing all adversities was associated with an estimated change in the prevalence of offspring common mental disorders from 10.2% to 7.6% and an improvement in school grades with an SD of 0.149 (95% CI, 0.147-0.149). Preventing parental separation provided for the greatest improvement, with an estimated 2.34% (95% CI, 2.23%-2.42%) fewer children with a common mental disorder and an improvement in school grades by 0.127 SDs (0.125-0.129). Greater improvements were shown by hypothetically targeting adolescents (age 12-16 years) and those whose parents had a mental illness when the child was born. Conclusions and Relevance: The results of this cohort modeling study suggest that preventing childhood adversity could provide notable improvements in the rates of common mental disorders and school grades. Many children might achieve better life outcomes if resources are properly allocated to the right adversities (parental separation), the right groups (children with parental mental illness), and at the right time (adolescence).