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Hybridization allows adaptations to be shared among lineages and may trigger the evolution of new species1,2. However, convincing examples of homoploid hybrid speciation remain rare because it is challenging to demonstrate that hybridization was crucial in generating reproductive isolation3. Here we combine population genomic analysis with quantitative trait locus mapping of species-specific traits to examine a case of hybrid speciation in Heliconius butterflies. We show that Heliconius elevatus is a hybrid species that is sympatric with both parents and has persisted as an independently evolving lineage for at least 180,000 years. This is despite pervasive and ongoing gene flow with one parent, Heliconius pardalinus, which homogenizes 99% of their genomes. The remaining 1% introgressed from the other parent, Heliconius melpomene, and is scattered widely across the H. elevatus genome in islands of divergence from H. pardalinus. These islands contain multiple traits that are under disruptive selection, including colour pattern, wing shape, host plant preference, sex pheromones and mate choice. Collectively, these traits place H. elevatus on its own adaptive peak and permit coexistence with both parents. Our results show that speciation was driven by introgression of ecological traits, and that speciation with gene flow is possible with a multilocus genetic architecture.
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Mariposas Diurnas , Introgresión Genética , Especiación Genética , Hibridación Genética , Sitios de Carácter Cuantitativo , Animales , Femenino , Masculino , Mariposas Diurnas/anatomía & histología , Mariposas Diurnas/clasificación , Mariposas Diurnas/genética , Flujo Génico , Introgresión Genética/genética , Genoma de los Insectos/genética , Preferencia en el Apareamiento Animal , Fenotipo , Pigmentación/genética , Sitios de Carácter Cuantitativo/genética , Aislamiento Reproductivo , Selección Genética/genética , Especificidad de la Especie , Simpatría/genética , Alas de Animales/anatomía & histología , Alas de Animales/metabolismoRESUMEN
During Hedgehog (Hh) signal transduction in development and disease, the atypical G protein-coupled receptor (GPCR) SMOOTHENED (SMO) communicates with GLI transcription factors by binding the protein kinase A catalytic subunit (PKA-C) and physically blocking its enzymatic activity. Here, we show that GPCR kinase 2 (GRK2) orchestrates this process during endogenous mouse and zebrafish Hh pathway activation in the primary cilium. Upon SMO activation, GRK2 rapidly relocalizes from the ciliary base to the shaft, triggering SMO phosphorylation and PKA-C interaction. Reconstitution studies reveal that GRK2 phosphorylation enables active SMO to bind PKA-C directly. Lastly, the SMO-GRK2-PKA pathway underlies Hh signal transduction in a range of cellular and in vivo models. Thus, GRK2 phosphorylation of ciliary SMO and the ensuing PKA-C binding and inactivation are critical initiating events for the intracellular steps in Hh signaling. More broadly, our study suggests an expanded role for GRKs in enabling direct GPCR interactions with diverse intracellular effectors.
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Cilios , Proteínas Quinasas Dependientes de AMP Cíclico , Quinasa 2 del Receptor Acoplado a Proteína-G , Proteínas Hedgehog , Transducción de Señal , Receptor Smoothened , Pez Cebra , Animales , Cilios/metabolismo , Receptor Smoothened/metabolismo , Receptor Smoothened/genética , Proteínas Hedgehog/metabolismo , Quinasa 2 del Receptor Acoplado a Proteína-G/metabolismo , Ratones , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Pez Cebra/metabolismo , Fosforilación , Proteínas de Pez Cebra/metabolismo , Proteínas de Pez Cebra/genética , Células 3T3 NIHRESUMEN
How cellular adaptations give rise to opioid analgesic tolerance to opioids like morphine is not well understood. For one, pain is a complex phenomenon comprised of both sensory and affective components, largely mediated through separate circuits. Glutamatergic projections from the medial thalamus (MThal) to the anterior cingulate cortex (ACC) are implicated in processing of affective pain, a relatively understudied component of the pain experience. The goal of this study was to determine the effects of chronic morphine exposure on mu-opioid receptor (MOR) signaling on MThal-ACC synaptic transmission within the excitatory and feedforward inhibitory pathways. Using whole-cell patch clamp electrophysiology and optogenetics to selectively target these projections, we measured morphine-mediated inhibition of optically evoked postsynaptic currents in ACC layer V pyramidal neurons in drug-naïve and chronically morphine treated mice. We found that that morphine perfusion inhibited the excitatory and feedforward inhibitory pathways similarly in females but caused greater inhibition of the inhibitory pathway in males. Chronic morphine treatment robustly attenuated morphine presynaptic inhibition within the inhibitory pathway in males, but not females, and mildly attenuated presynaptic inhibition within the excitatory pathway in both sexes. These effects were not observed in MOR phosphorylation-deficient mice. This study indicates that chronic morphine treatment induces cellular tolerance to morphine within a thalamo-cortical circuit relevant to pain and opioid analgesia. Furthermore, it suggests this tolerance may be driven by MOR phosphorylation. Overall, these findings improve our understanding of how chronic opioid exposure alters cellular signaling in ways that may contribute to opioid analgesic tolerance.
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Studies of adaptive radiations have played a central role in our understanding of reproductive isolation. Yet the focus has been on human-biased visual and auditory signals, leaving gaps in our knowledge of other modalities. To date, studies on chemical signals in adaptive radiations have focused on systems with multimodal signalling, making it difficult to isolate the role chemicals play in reproductive isolation. In this study we examine the use of chemical signals in the species recognition and adaptive radiation of Hawaiian Tetragnatha spiders by focusing on entire communities of co-occurring species, and conducting behavioural assays in conjunction with chemical analysis of their silks using gas chromatography-mass spectrometry. Male spiders significantly preferred the silk extracts of conspecific mates over those of sympatric heterospecifics. The compounds found in the silk extracts, long chain alkyl methyl ethers, were remarkably species-specific in the combination and quantity. The differences in the profile were greatest between co-occurring species and between closely related sibling species. Lastly, there were significant differences in the chemical profile between two populations of a particular species. These findings provide key insights into the role chemical signals play in the attainment and maintenance of reproductive barriers between closely related co-occurring species.
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Arañas , Animales , Humanos , Masculino , Hawaii , Especificidad de la Especie , Aislamiento Reproductivo , SedaRESUMEN
Springtails use unique compounds for their outermost epicuticular wax layer, often of terpenoid origin. We report here the structure and synthesis of socialane, the major cuticular constituent of the Collembola Hypogastrura socialis. Socialane is also the first regular nonaprenyl terpene with a cyclic head group. The saturated side chain has seven stereogenic centers, making the determination of the configuration difficult. We describe here the identification of socialane and a synthetic approach using the building blocks farnesol and phytol, enantioselective hydrogenation, and α-alkylation of sulfones for the synthesis of various stereoisomers. NMR experiments showed the presence of an anti-configuration of the methyl groups closest to the benzene ring and that the other methyl groups of the polyprenyl side-chain are not uniformly configured. Furthermore, socialane is structurally different from [6+2]-terpene viaticene of the closely related H. viatica, showing species specificity of the epicuticular lipids of this genus and hinting at a possible role of surface lipids in the communication of these gregarious arthropods.
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Artrópodos , Terpenos , Animales , Estereoisomerismo , Terpenos/química , Artrópodos/química , Lípidos/química , Farnesol/química , Farnesol/análogos & derivados , Fitol/química , Espectroscopía de Resonancia Magnética , HidrogenaciónRESUMEN
OBJECTIVE: Little information is available concerning protein expression of the free fatty acid receptor 2 (FFAR2), especially in tumours. Therefore, the aim of the present study was to comprehensively characterise the expression profile of FFAR2 in a large series of human normal and neoplastic tissues using immunohistochemistry thus providing a basis for further in-depth investigations into its potential diagnostic or therapeutic importance. METHODS: We developed a novel rabbit polyclonal anti-FFAR2 antibody, 0524, directed against the C-terminal region of human FFAR2. Antibody specificity was confirmed via Western blot analyses and immunocytochemistry using the FFAR2-expressing cell line BON-1 and FFAR2-specific small interfering RNA as well as native and FFAR2-transfected HEK-293 cells. The antibody was then used for immunohistochemical analyses of various formalin-fixed, paraffin-embedded specimens of normal and neoplastic human tissues. RESULTS: In normal tissues, FFAR2 was mainly present in distinct cell populations of the cerebral cortex, follicular cells and C cells of the thyroid, cardiomyocytes of the heart, bronchial epithelia and glands, hepatocytes and bile duct epithelia of the liver, gall bladder epithelium, exocrine and ß-cells of the endocrine pancreas, glomerular mesangial cells and podocytes as well as collecting ducts of the kidney, intestinal mucosa (particularly enteroendocrine cells), prostate epithelium, seminiferous tubules of the testicles, and placental syncytiotrophoblasts. In neoplastic tissues, FFAR2 was particularly prevalent in papillary thyroid carcinomas, parathyroid adenomas, and gastric, colon, pancreatic, hepatocellular, cholangiocellular, urinary bladder, breast, cervical, and ovarian carcinomas. CONCLUSIONS: We generated and characterised a novel rabbit polyclonal anti-human FFAR2 antibody that is well-suited for visualising FFAR2 expression in human routine pathology tissues. This antibody is also suitable for Western blot and immunocytochemistry experiments. To our knowledge, this antibody enabled the first broad FFAR2 protein expression profile in various normal and neoplastic human tissues.
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Neoplasias , Humanos , Neoplasias/metabolismo , Neoplasias/patología , Neoplasias/genética , Células HEK293 , Animales , Conejos , Inmunohistoquímica , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Femenino , MasculinoRESUMEN
Synthetic routes to geosmin and its enantiomer are well established, but the enantioselective synthesis of stereoisomers of geosmin is unknown. Here a stereoselective synthesis of all stereoisomers of geosmin is reported, yielding all compounds in high enantiomeric purity. Furthermore, the stereoselective synthesis of a geosmin derivative isolated from a mangrove associated streptomycete was performed, establishing the absolute configuration of the natural product. Finally, a new side product of the geosmin synthase from Streptomyces ambofaciens was isolated and its structure was elucidated by NMR spectroscopy. The absolute configuration of this new compound was determined through a stereoselective synthesis.
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Productos Biológicos , Naftoles , Streptomyces , Estereoisomerismo , Productos Biológicos/química , Productos Biológicos/síntesis química , Naftoles/química , Naftoles/síntesis química , Streptomyces/química , Estructura MolecularRESUMEN
Collembola are closely related to insects, but our knowledge of their often unique chemistry is limited. Here we report the identification of the epicuticular lipid nitidane, representing a novel class of epicuticular lipids. Nitidane (4) is an irregular terpene consisting of seven isoprene units, made up of a diterpene core that is modified by a geranyl moiety that is itself prenylated. The observed [46+(22+11)1]-terpene structure has not been reported before.
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Diterpenos , Animales , Diterpenos/química , Diterpenos/aislamiento & purificación , Estructura Molecular , Prenilación , Lípidos/químicaRESUMEN
Pheromone communication is widespread among animals. Since it is often involved in mate choice, pheromone production is often tightly controlled. Although male sex pheromones (MSPs) and anti-aphrodisiacs have been studied in some Heliconius butterfly species, little is known about the factors affecting their production and release in these long-lived butterflies. Here, we investigate the effect of post-eclosion age on chemical blends from pheromone-emitting tissues in Heliconius atthis and Heliconius charithonia, exhibiting respectively free-mating and pupal-mating strategies that are hypothesised to differently affect the timing of their pheromone emissions. We focus on two different tissues: the wing androconia, responsible for MSPs used in courtship, and the genital tip, the production site for anti-aphrodisiac pheromones that affect post-mating behaviour. Gas chromatography-mass spectrometric analysis of tissue extracts from virgin males and females of both species from day 0 to 8 post-eclosion demonstrates the following. Some ubiquitous fatty acid precursors are already detectable at day 0. The complexity of the chemical blends increases with age regardless of tissue or sex. No obvious difference in the time course of blend production was evident between the two species, but female tissues in H. charithonia were more affected by age than in H. atthis. We suggest that compounds unique to male androconia and genitals and whose amount increases with age are potential candidates for future investigation into their roles as pheromones. While this analysis revealed some of the complexity in Heliconius chemical ecology, the effects of other factors, such as the time of day, remain unknown.
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Mariposas Diurnas , Cromatografía de Gases y Espectrometría de Masas , Atractivos Sexuales , Animales , Mariposas Diurnas/fisiología , Masculino , Femenino , Atractivos Sexuales/metabolismo , Atractivos Sexuales/análisis , Atractivos Sexuales/química , Maduración Sexual , Alas de Animales/fisiología , Alas de Animales/química , Conducta Sexual AnimalRESUMEN
BACKGROUND: Oxygen saturation, a key indicator of COVID-19 severity, poses challenges, especially in cases of silent hypoxemia. Electronic health records (EHRs) often contain supplemental oxygen information within clinical narratives. Streamlining patient identification based on oxygen levels is crucial for COVID-19 research, underscoring the need for automated classifiers in discharge summaries to ease the manual review burden on physicians. METHOD: We analysed text lines extracted from anonymised COVID-19 patient discharge summaries in German to perform a binary classification task, differentiating patients who received oxygen supplementation and those who did not. Various machine learning (ML) algorithms, including classical ML to deep learning (DL) models, were compared. Classifier decisions were explained using Local Interpretable Model-agnostic Explanations (LIME), which visualize the model decisions. RESULT: Classical ML to DL models achieved comparable performance in classification, with an F-measure varying between 0.942 and 0.955, whereas the classical ML approaches were faster. Visualisation of embedding representation of input data reveals notable variations in the encoding patterns between classic and DL encoders. Furthermore, LIME explanations provide insights into the most relevant features at token level that contribute to these observed differences. CONCLUSION: Despite a general tendency towards deep learning, these use cases show that classical approaches yield comparable results at lower computational cost. Model prediction explanations using LIME in textual and visual layouts provided a qualitative explanation for the model performance.
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COVID-19 , Compuestos de Calcio , Óxidos , Humanos , Estudios Retrospectivos , Oxígeno , Suplementos DietéticosRESUMEN
Land Surface Temperature (LST) is an important resource for a variety of tasks. The data are mostly free of charge and combine high spatial and temporal resolution with reliable data collection over a historical timeframe. When remote sensing is used to provide LST data, such as the MODA11 product using information from the MODIS sensors attached to NASA satellites, data acquisition can be hindered by clouds or cloud shadows, occluding the sensors' view on different areas of the world. This makes it difficult to take full advantage of the high resolution of the data. A common solution to interpolating LST data is statistical interpolation methods, such as fitting polynomials or thin plate spine interpolation. These methods have difficulties in incorporating additional knowledge about the research area and learning local dependencies that can help with the interpolation process. We propose a novel approach to interpolating remote sensing LST data in a fixed research area considering local ground-site air temperature measurements. The two-step approach consists of learning the LST from air temperature measurements, where the ground-site weather stations are located, and interpolating the remaining missing values with partial convolutions within a U-Net deep learning architecture. Our approach improves the interpolation of LST for our research area by 44% in terms of RMSE, when compared to state-of-the-art statistical methods. Due to the use of air temperature, we can provide coverage of 100%, even when no valid LST measurements were available. The resulting gapless coverage of high resolution LST data will help unlock the full potential of remote sensing LST data.
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Annotated language resources derived from clinical routine documentation form an intriguing asset for secondary use case scenarios. In this investigation, we report on how such a resource can be leveraged to identify additional term candidates for a chosen set of ICD-10 codes. We conducted a log-likelihood analysis, considering the co-occurrence of approximately 1.9 million de-identified ICD-10 codes alongside corresponding brief textual entries from problem lists in German. This analysis aimed to identify potential candidates with statistical significance set at p < 0.01, which were used as seed terms to harvest additional candidates by interfacing to a large language model in a second step. The proposed approach can identify additional term candidates at suitable performance values: hypernyms MAP@5=0.801, synonyms MAP@5 = 0.723 and hyponyms MAP@5 = 0.507. The re-use of existing annotated clinical datasets, in combination with large language models, presents an interesting strategy to bridge the lexical gap in standardized clinical terminologies and real-world jargon.
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Clasificación Internacional de Enfermedades , Procesamiento de Lenguaje Natural , Vocabulario Controlado , Humanos , Terminología como Asunto , Registros Electrónicos de Salud/clasificación , AlemaniaRESUMEN
OBJECTIVE: To assess the performance of large language models (LLMs) for zero-shot disambiguation of acronyms in clinical narratives. MATERIALS AND METHODS: Clinical narratives in English, German, and Portuguese were applied for testing the performance of four LLMs: GPT-3.5, GPT-4, Llama-2-7b-chat, and Llama-2-70b-chat. For English, the anonymized Clinical Abbreviation Sense Inventory (CASI, University of Minnesota) was used. For German and Portuguese, at least 500 text spans were processed. The output of LLM models, prompted with contextual information, was analyzed to compare their acronym disambiguation capability, grouped by document-level metadata, the source language, and the LLM. RESULTS: On CASI, GPT-3.5 achieved 0.91 in accuracy. GPT-4 outperformed GPT-3.5 across all datasets, reaching 0.98 in accuracy for CASI, 0.86 and 0.65 for two German datasets, and 0.88 for Portuguese. Llama models only reached 0.73 for CASI and failed severely for German and Portuguese. Across LLMs, performance decreased from English to German and Portuguese processing languages. There was no evidence that additional document-level metadata had a significant effect. CONCLUSION: For English clinical narratives, acronym resolution by GPT-4 can be recommended to improve readability of clinical text by patients and professionals. For German and Portuguese, better models are needed. Llama models, which are particularly interesting for processing sensitive content on premise, cannot yet be recommended for acronym resolution.
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Abreviaturas como Asunto , Procesamiento de Lenguaje Natural , Humanos , Lenguaje , Narración , Registros Electrónicos de SaludRESUMEN
This paper focuses on the development of electroplating on 150 mm wafer level for microsystem technology applications from 1-Ethyl-3-methylimidazolium chloride (EMImCl) with Aluminumtrichloride (AlCl3). The deposition was carried out on 150 mm wafers with Au or Al seed layers deposited by physical vapor deposition (PVD). The electrodeposition was carried out using pattern plating. On the Au seed layer, bipolar pulse plating was applied. Compared to the Au seed layer, the electrodeposition on the Al seed layer was favorable, with lower current densities and pulsing frequencies. Utilizing the recurrent galvanic pulses and avoiding ionic liquid convection, inhomogeneities lower than 15% were achieved with a laboratory plating cell. One major aspect of this study was the removal of the native Al oxide prior to deposition. It was investigated on the chip and wafer levels using either current- or potential-controlled removal pulses. This process step was affected by the plasma treatment of the wafer, thus the surface free energy, prior to plating. It turned out that a higher surface free energy hindered proper oxide removal at a potential of 3 V. The theory of oxide breakdown based on electrostriction force via the electrical field was applied to discuss the findings and to derive conclusions for future plating experiments.
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This paper presents a versatile solution to formally represent the contents of electronic health records. It is based on the knowledge graph paradigm, and semantic web standards RDF and OWL. It employs the established semantic standards SNOMED CT and FHIR, which warrant international interoperability. A graph-based form is not only useful to feed different target visualizations, but it can also be subject to AI-powered services such as (fuzzy) retrieval and summarization.
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Registros Electrónicos de Salud , Humanos , Web Semántica , Systematized Nomenclature of Medicine , Medicina de Precisión , Semántica , Gráficos por Computador , Almacenamiento y Recuperación de la InformaciónRESUMEN
International interoperability of healthcare and research data requires a commitment to standards. To this end, SNOMED CT was evaluated for representing questionnaire items of the European Registry of Stroke Care Quality using a complex annotation protocol. The agreement between validators and annotators was 72.4%. At least 64% of the information could be represented by using SNOMED CT only, including complex post-coordinations. 9% of the information would require an information model, and 14% the addition of new content to SNOMED CT. Next steps will be the creation of an annotation guideline for questionnaires, a specific reference set, and the combination of both with an information model such as HL7 FHIR.
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Sistema de Registros , Accidente Cerebrovascular , Systematized Nomenclature of Medicine , Humanos , Encuestas y Cuestionarios , Europa (Continente) , Registros Electrónicos de Salud/normasRESUMEN
Advancements in digitalisation with cardiac implantable electronic devices (CIEDs) allow patients opportunities for improved autonomy, quality of life, and a potential increase in life expectancy. However, with the digital and functional practicalities of CIEDs, there exists also cyber safety issues with transferring wireless information. If a digital network were to be hacked, a CIED patient could experience both the loss of sensitive data and the loss of functional control of the CIED due to an unwelcome party. Moreover, if a CIED patient were to become victim of a cyber attack, which resulted in a serious or lethal event, and if this information were to become public, the trust in healthcare would be impacted and legal consequences could result. A cyber attack therefore poses not only a direct threat to the patient's health but also the confidentiality, integrity, and availability of the CIED, and these cyber threats could be considered "patient-targeted threats." Informed consent is a key component of ethical care, legally concordant practice, and promoting patient-as-partner therapeutic relationships [1]. To date, there are no standardised guidelines for listing cybersecurity risks within the informed consent or for discussing them during the consent process. Providers are responsible for adhering to the ethical principles of autonomy, beneficence, non-maleficence, and justice, both in medical practice generally and the informed consent process specifically. At present, the decision to include cybersecurity risks is mainly left to the provider's discretion, who may also have limited cyber risk information. Without effective and in-depth communication about all possible cybersecurity risks during the consent process, CIED patients can be left unaware of the privacy and physical risks they possess by carrying such a device. Therefore, cyber risk factors should be covered within the patients' informed consent and reviewed on an ongoing basis as new risk information becomes available. By including cyber risk information in the informed consent process, patients are given the autonomy to make the best-informed decision.
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We present a data visualization tool for tumor boards, merging clinical with molecular and multi-omics data to refine precision oncology decisions. The tool offers a holistic patient perspective, facilitating personalized treatment strategies. By integrating clinical and laboratory datasets, it enables intuitive navigation through complex information. Clinicians are supported in their decision-making by user-friendly visualizations. Future studies are needed to evaluate its real-world impact and usability in precision oncology settings.
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Neoplasias , Medicina de Precisión , Humanos , Interfaz Usuario-Computador , Oncología Médica , Visualización de Datos , Sistemas de Apoyo a Decisiones ClínicasRESUMEN
The salinilactones, volatile marine natural products secreted from Salinispora arenicola, feature a unique [3.1.0]-lactone ring system and cytotoxic activities through a hitherto unknown mechanism. To find their molecular target, an activity-based protein profiling with a salinilactone-derived probe is applied that disclosed the protein disulfide-isomerases (PDIs) as the dominant mammalian targets of salinilactones, and thioredoxin (TRX1) as secondary target. The inhibition of protein disulfide-isomerase A1 (PDIA1) and TRX1 is confirmed by biochemical assays with recombinant proteins, showing that (1S,5R)-salinilactone B is more potent than its (1R,5S)-configured enantiomer. The salinilactones bound covalently to C53 and C397, the catalytically active cysteines of the isoform PDIA1 according to tandem mass spectrometry. Reactions with a model substrate demonstrated that the cyclopropyl group is opened by an attack of the thiol at C6. Fluorophore labeling experiments showed the cell permeability of a salinilactone-BODIPY (dipyrrometheneboron difluoride) conjugate and its co-localization with PDIs in the endoplasmic reticulum. The study is one of the first to pinpoint a molecular target for a volatile microbial natural product, and it demonstrates that salinilactones can achieve high selectivity despite their small size and intrinsic reactivity.
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Proteína Disulfuro Isomerasas , Proteína Disulfuro Isomerasas/metabolismo , Proteína Disulfuro Isomerasas/química , Humanos , Lactonas/metabolismo , Lactonas/químicaRESUMEN
Agonist-induced phosphorylation is a crucial step in the activation/deactivation cycle of G protein-coupled receptors (GPCRs), but direct determination of individual phosphorylation events has remained a major challenge. We have recently developed a bead-based immunoassay for the quantitative assessment of agonist-induced GPCR phosphorylation that can be performed entirely in 96-well plates, thus eliminating the need for western blot analysis. In the present study, we adapted this assay to three novel phosphosite-specific antibodies directed against the neurokinin 1 (NK1) receptor, namely pS338/pT339-NK1, pT344/pS347-NK1, and pT356/pT357-NK1. We found that substance P (SP) stimulated concentration-dependent phosphorylation of all three sites, which could be completely blocked in the presence of the NK1 receptor antagonist aprepitant. The other two endogenous ligands of the tachykinin family, neurokinin A (NKA) and neurokinin B (NKB), were also able to induce NK1 receptor phosphorylation, but to a much lesser extent than substance P. Interestingly, substance P promoted phosphorylation of the two distal sites more efficiently than that of the proximal site. The proximal site was identified as a substrate for phosphorylation by protein kinase C. Analysis of GPCR kinase (GRK)-knockout cells revealed that phosphorylation was mediated by all four GRK isoforms to similar extents at the T344/S347 and the T356/T357 cluster. Knockout of all GRKs resulted in abolition of all phosphorylation signals highlighting the importance of these kinases in agonist-mediated receptor phosphorylation. Thus, the 7TM phosphorylation assay technology allows for rapid and detailed analyses of GPCR phosphorylation.