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The main objective of this study was to determine whether the common Y-haplogroups were be associated with the risk of developing severe COVID-19 in Spanish male. We studied 479 patients who required hospitalization due to COVID-19 and 285 population controls from the region of Asturias (northern Spain), They were genotyped for several polymorphisms that define the common European Y-haplogroups. We compared the frequencies between patients and controls aged ≤ 65 and >65 years. There were no different haplogroup frequencies between the two age groups of controls. Haplogroup R1b was less common in patients aged ≤65 years. Haplogroup I was more common in the two patient´s groups compared to controls (p = 0.02). Haplogroup R1b was significantly more frequent among hypertensive patients, without difference between the hypertensive and normotensive controls. This suggested that R1b could increase the risk for severe COVID-19 among male with pre-existing hypertension. In conclusion, we described the Y-haplogroup structure among Asturians. We found an increased risk of severe COVID-19 among haplogroup I carriers, and a significantly higher frequency of R1b among hypertensive patients. These results indicate that Y-chromosome variants could serve as markers to define the risk of developing a severe form of COVID-19.
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COVID-19 , Cromossomos Humanos Y , Haplótipos , Hipertensão , SARS-CoV-2 , Humanos , Masculino , COVID-19/genética , COVID-19/epidemiologia , Espanha/epidemiologia , Haplótipos/genética , Idoso , Pessoa de Meia-Idade , SARS-CoV-2/genética , Cromossomos Humanos Y/genética , Hipertensão/genética , Predisposição Genética para Doença , Estudos de Casos e Controles , Polimorfismo de Nucleotídeo Único , Adulto , FemininoRESUMO
The singular BRCA1/2 mutational landscape of Asturias is updated 10 years after the first study. We analyzed BRCA1 and BRCA2 pathogenic variants in 1653 index cases. In total, 238 families were identified to carry a pathogenic variant, 163 families in BRCA1 and 75 families in BRCA2. This yielded a prevalence rate of 14.4%. Seven recurrent variants were found accounting for 55% of the cases. Among them, three are widely distributed (BRCA1 c.211A>G, c.470_471del and c.3331_3334del) and four had been reported as novel in Asturias: two in BRCA1 (c.1674del and c.2901_2902dup) and two in BRCA2 (c.2095C>T and c.4040_4035delinsC). A common haplotype was established for all recurrent variants indicating a shared ancestral origin. Three splicing analyses are shown: BRCA1:c.5152+3A>C and BRCA1:c.5333-3T>G that lead to skipping of exon 18, and 22 respectively, and BRCA1:c.5278-1G>T giving rise to two transcripts, one lacking exon 21 (p.Ille1760Glyfs*60) and one lacking the first 8 nucleotides of exon 21 (p.Phe1761Asnfs*14), supporting pathogenicity for these variants.
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Proteína BRCA1 , Proteína BRCA2 , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Mutação em Linhagem Germinativa/genética , Espanha/epidemiologia , Proteína BRCA1/genética , Feminino , Proteína BRCA2/genética , Adulto , Pessoa de Meia-Idade , Haplótipos/genética , Linhagem , Éxons/genética , Neoplasias da Mama/genética , Neoplasias da Mama/epidemiologia , MasculinoRESUMO
The nanocrystal (NC) technology has become one of the most commonly used strategies for the formulation of poorly soluble actives. Given their large specific surface, NCs are mainly used to enhance the oral absorption of poorly soluble actives. Differently from conventional nanoparticles, which require the use of carrier materials and have limited drug loadings, NCs' drug loading approaches 100% since they are formed of the pure drug and surrounded by a thin layer of a stabilizer. In this work, we report the covalent decoration of curcumin NCs with folic acid (FA) using EDC/NHS chemistry and explore the novel systems as highly loaded "Trojan horses" to target cancer cells. The decorated NCs demonstrated a remarkable improvement in curcumin uptake, exhibiting enhanced growth inhibition in cancer cells (HeLa and MCF7) while sparing healthy cells (J774A.1). Cellular uptake studies revealed significantly heightened entry of FA-decorated NCs into cancer cells compared to unmodified NCs while also showing reduced uptake by macrophages, indicating a potential for prolonged circulation in vivo. These findings underline the potential of NC highly loaded nanovectors for drug delivery and, in particular, for cancer therapies, effectively targeting folate receptor-overexpressing cells while evading interception by macrophages, thus preserving their viability and offering a promising avenue for precise and effective treatments.
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Curcumina , Ácido Fólico , Nanopartículas , Ácido Fólico/química , Humanos , Nanopartículas/química , Curcumina/farmacologia , Curcumina/química , Curcumina/farmacocinética , Curcumina/administração & dosagem , Animais , Células MCF-7 , Células HeLa , Sistemas de Liberação de Medicamentos/métodos , Camundongos , Portadores de Fármacos/química , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Sobrevivência Celular/efeitos dos fármacos , Linhagem Celular TumoralRESUMO
Fluorine (19 F) incorporation into glycan-binding proteins (lectins) has been achieved and exploited to monitor the binding to carbohydrate ligands by nuclear magnetic resonance (NMR) spectroscopy. Galectins are a family of lectins that bind carbohydrates, generally with weak affinities, through a combination of intermolecular interactions including a key CH-π stacking involving a conserved tryptophan residue. Herein, Galectin-3 (Gal3) and Galectin-8 (Gal8) with one and two carbohydrate recognition domains (CRDs), respectively, were selected. Gal3 contains one Trp, whereas Gal8 contains three, one at each binding site and a third one not involved in sugar binding; these were substituted by the corresponding F-Trp analogues. The presence of fluorine did not significantly modify the affinity for glycan binding, which was in slow exchange on the 19 F NMR chemical-shift timescale, even for weak ligands, and allowed binding events taking place at two different binding sites within the same lectin to be individualized.
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Flúor , Galectinas , Galectinas/metabolismo , Carboidratos , Polissacarídeos/química , Sítios de Ligação , Espectroscopia de Ressonância Magnética , Galectina 3/metabolismoRESUMO
We herein report the first total synthesis of the Streptococcus pneumoniae serotype 1 (Sp1) oligosaccharide, a unique zwitterionic capsular polysaccharide carrying labile O-acetyl esters. The target oligosaccharides, featuring rare α-2,4-diamino-2,4,6-trideoxy galactose (AAT) and α-galacturonic acids, were assembled up to the 9-mer level, in a highly stereoselective manner using trisaccharide building blocks. The lability of the O-acetyl esters imposed a careful deprotection scheme to prevent migration and hydrolysis. The migration was investigated in detail at various pD values using NMR spectroscopy, to show that migration and hydrolysis of the C-3-O-acetyl esters readily takes place under neutral conditions. Structural investigation showed the oligomers to adopt a right-handed helical structure with the acetyl esters exposed on the periphery of the helix in close proximity of the neighboring AAT residues, thereby imposing conformational restrictions on the AATα1-4GalA(3OAc) glycosidic linkages, supporting the helical shape of the polysaccharide, that has been proposed to be critical for its unique biological activity.
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Polissacarídeos Bacterianos , Streptococcus pneumoniae , Polissacarídeos Bacterianos/química , Oligossacarídeos , Trissacarídeos/química , GlicosídeosRESUMO
Climate change scenarios have significant implications for the livelihoods and food security of particular groups in society and will necessitate a range of adaptation actions. While there is a significant literature on the social as well as biophysical factors and limits to adaptation, less is known about the interactions between these, and what such interactions mean for the prospects of achieving sustainable and resilient food systems. This paper is an attempt at addressing this gap by examining changing biophysical and social factors, with specific consideration of vulnerable groups, across four case studies (Ghana, Malawi, Norway and Spain). In each case, future climate change scenarios and associated biophysical limits are mapped onto four key social factors that drive vulnerability and mediate adaptation, namely, scale, history, power and politics, and social differentiation. We then consider what the interaction between biophysical limits and socio-political dynamics means for the options for and limits to future adaptation, and how climate may interact with, and reshape, socio-political elements. We find that biophysical limits and socio-political factors do not operate in isolation, but interact, with dynamic relationships determining the 'space' or set of options for sustainable adaptation. By connecting the perspectives of biophysical and social factors, the study illuminates the risks of unanticipated outcomes that result from the disregard of local contexts in the implementation of adaptation measures. We conclude that a framework focusing on the space for sustainable adaptation conditioned by biophysical and social factors, and their interactions, can help provide evidence on what does and does not constitute sustainable adaptation, and help to counter unhelpful narratives of climate change as a sole or dominant cause of challenges in food systems.
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Aclimatação , Mudança Climática , Adaptação Fisiológica , Previsões , EspanhaRESUMO
The use of MW allows the efficient palladium(II)-catalysed C-3 acylation of thiophenes with aldehydes via C(sp2)-H activation for the synthesis of (cyclo)alkyl/aryl thienyl ketones (43 examples). Compared to standard thermal conditions, the use of MW reduces the reaction time (15 to 30 min vs. 1 to 3 hours), leading to improved yields of the ketones (up to 92%). The control of positional selectivity is achieved by 2-pyridinyl and 2-pyrimidyl ortho-directing groups at C-2 of the thiophene scaffold. To show the synthetic applicability, selected ketones were subjected to further transformations, including intramolecular reactions to directly embed the directing group in the core structure of the new molecule.
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1,2,3-Triazolylidene MIC M-complexes (M = Au, Pd, Pt) having 2-azetidinones and penicillin G substituents at the triazole ring were prepared by CuAAC on 2-azetidinones having a terminal alkyne tethered at N1, followed by alkylation of the 1,2,3-triazole ring and transmetallation [Au(I), Pd(II) and Pt(II)]. The Au-MIC complexes efficiently catalyze the regioselective cycloisomerization of enynes, while the Pt-MIC complexes were efficient catalysts in hydrosilylation reactions.
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Complexos de Coordenação , Metano/análogos & derivados , Penicilinas , Triazóis , beta-LactamasRESUMO
Eradicating world hunger-the aim of Sustainable Development Goal 2 (SDG2)-requires a social-ecological approach to agrifood systems. However, previous work has mostly focused on one or the other. Here, we apply such a holistic approach to depicting the global food panorama through a quantitative multivariate assessment of 43 indicators of food sovereignty and 28 indicators of sociodemographics, social being, and environmental sustainability in 150 countries. The results identify 5 world regions and indicate the existence of an agrifood debt (i.e., disequilibria between regions in the natural resources consumed, the environmental impacts produced, and the social wellbeing attained by populations that play different roles within the globalized agrifood system). Three spotlights underpin this debt: 1) a severe contrast in diets and food security between regions, 2) a concern about the role that international agrifood trade is playing in regional food security, and 3) a mismatch between regional biocapacity and food security. Our results contribute to broadening the debate beyond food security from a social-ecological perspective, incorporating environmental and social dimensions.
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Genomic resources for the domestic dog have improved with the widespread adoption of a 173k SNP array platform and updated reference genome. SNP arrays of this density are sufficient for detecting genetic associations within breeds but are underpowered for finding associations across multiple breeds or in mixed-breed dogs, where linkage disequilibrium rapidly decays between markers, even though such studies would hold particular promise for mapping complex diseases and traits. Here we introduce an imputation reference panel, consisting of 365 diverse, whole-genome sequenced dogs and wolves, which increases the number of markers that can be queried in genome-wide association studies approximately 130-fold. Using previously genotyped dogs, we show the utility of this reference panel in identifying potentially novel associations, including a locus on CFA20 significantly associated with cranial cruciate ligament disease, and fine-mapping for canine body size and blood phenotypes, even when causal loci are not in strong linkage disequilibrium with any single array marker. This reference panel resource will improve future genome-wide association studies for canine complex diseases and other phenotypes.
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Estudo de Associação Genômica Ampla/métodos , Genômica/métodos , Sequenciamento Completo do Genoma/métodos , Animais , Cruzamento , Mapeamento Cromossômico/métodos , Cães/genética , Genoma/genética , Genótipo , Desequilíbrio de Ligação/genética , Fenótipo , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
Weight gain is a hallmark of decreased estradiol (E2) levels because of menopause or following surgical ovariectomy (OVX) at younger ages. Of note, this weight gain tends to be around the abdomen, which is frequently associated with impaired metabolic homeostasis and greater cardiovascular risk in both rodents and humans. However, the molecular underpinnings and the neuronal basis for these effects remain to be elucidated. The aim of this study is to elucidate whether the kappa-opioid receptor (k-OR) system is involved in mediating body weight changes associated with E2 withdrawal. Here, we document that body weight gain induced by OVX occurs, at least partially, in a k-OR dependent manner, by modulation of energy expenditure independently of food intake as assessed in Oprk1-/-global KO mice. These effects were also observed following central pharmacological blockade of the k-OR system using the k-OR-selective antagonist PF-04455242 in wild type mice, in which we also observed a decrease in OVX-induced weight gain associated with increased UCP1 positive immunostaining in brown adipose tissue (BAT) and browning of white adipose tissue (WAT). Remarkably, the hypothalamic mTOR pathway plays an important role in regulating weight gain and adiposity in OVX mice. These findings will help to define new therapies to manage metabolic disorders associated with low/null E2 levels based on the modulation of central k-OR signaling.
Assuntos
Ingestão de Alimentos , Receptores Opioides kappa , Tecido Adiposo Marrom/metabolismo , Animais , Peso Corporal , Metabolismo Energético , Estrogênios/metabolismo , Feminino , Humanos , Camundongos , Obesidade/tratamento farmacológico , Obesidade/etiologia , Obesidade/metabolismo , Ovariectomia/efeitos adversos , Receptores Opioides kappa/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Aumento de PesoRESUMO
When the [Ru(p-cymene)(µ-Cl)Cl]2 complex is made to react, in dichloromethane, with the following ligands: 2-aminobenzonitrile (2abn), 4-aminobenzonitrile (4abn), 2-aminopyridine (2ampy) and 4-aminopyridine (4ampy), after addition of hexane, the following compounds are obtained: [Ru(p-cymene)Cl2(2abn)] (I), [Ru(p-cymene)Cl2(4abn)] (II), [Ru(p-cymene)Cl2(2ampy] (III) and [Ru(p-cymene)Cl2(µ-(4ampy)] (IV). All the compounds are characterized by elemental analysis of carbon, hydrogen and nitrogen, proton nuclear magnetic resonance, COSY 1H-1H, high-resolution mass spectrometry (ESI), thermogravimetry and single-crystal X-ray diffraction (the crystal structure of III is reported and compared with the closely related literature of II). The cytotoxicity effects of complexes were described for cervical cancer HeLa cells via 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) assay. The results demonstrate a low in vitro anticancer potential of the complexes.
Assuntos
Antineoplásicos , Complexos de Coordenação , Neoplasias , Rutênio , Humanos , Rutênio/química , Células HeLa , Complexos de Coordenação/química , Linhagem Celular Tumoral , Antineoplásicos/químicaRESUMO
Viral and/or host factors that are directly responsible for the acute versus chronic outcome of hepatitis B virus (HBV) infection have not been identified yet. Information on immune response during the early stages of HBV infection in humans is mainly derived from blood samples of patients with acute hepatitis B (AHB), which are usually obtained after the onset of clinical symptoms. Features of intrahepatic immune response in these patients are less studied due to the difficulty of obtaining multiple liver biopsies. Woodchuck hepatitis virus (WHV) infection in woodchucks is a model for HBV infection in humans. In the present study, five adult woodchucks were experimentally infected with WHV and then followed for 18 weeks. Blood and liver tissues were frequently collected for assaying markers of WHV replication and innate and adaptive immune responses. Liver tissues were further analyzed for pathological changes and stained for important immune cell subsets and cytokines. The increase and subsequent decline of viral replication markers in serum and liver, the elicitation of antibodies against viral proteins, and the induction of virus-specific T-cell responses indicated eventual resolution of acute WHV infection in all animals. Intrahepatic innate immune makers stayed unchanged immediately after the infection, but increased markedly during resolution, as determined by changes in transcript levels. The presence of interferon-gamma and expression of natural killer (NK) cell markers suggested that a non-cytolytic response mechanism is involved in the initial viral control in liver. This was followed by the expression of T-cell markers and cytolytic effector molecules, indicating the induction of a cytolytic response mechanism. Parallel increases in regulatory T-cell markers suggested that this cell subset participates in the overall immune cell infiltration in liver and/or has a role in regulating AHB induced by the cytolytic response mechanism. Since the transcript levels of immune cell markers in blood, when detectable, were lower than in liver, and the kinetics, except for NK-cells and interferon-gamma, did not correlate well with their intrahepatic expression, this further indicated enrichment of immune cells within liver. Conclusion: The coordinated interplay of innate and adaptive immunity mediates viral clearance in the woodchuck animal model of HBV infection. The initial presence of NK-cell associated interferon-gamma response points to an important role of this cytokine in HBV resolution.
Assuntos
Imunidade Adaptativa , Vírus da Hepatite B da Marmota/patogenicidade , Hepatite B/virologia , Imunidade Inata , Células Matadoras Naturais/virologia , Marmota/virologia , Envelhecimento , Animais , Vírus da Hepatite B da Marmota/imunologia , Interferon gama/metabolismo , Células Matadoras Naturais/metabolismo , Fígado/patologia , Fígado/virologia , Linfócitos T/imunologia , Linfócitos T/virologia , Replicação Viral/imunologiaRESUMO
A fragment screen of a library of 560 commercially available fragments using a kinetic assay identified a small molecule that increased the activity of the fungal glycoside hydrolase TrBgl2. An analogue by catalogue approach and detailed kinetic analysis identified improved compounds that behaved as nonessential activators with up to a 2-fold increase in maximum activation. The compounds did not activate the related bacterial glycoside hydrolase CcBglA demonstrating specificity. Interestingly, an analogue of the initial fragment inhibits both TrBgl2 and CcBglA, apparently through a mixed-model mechanism. Although it was not possible to determine crystal structures of activator binding to 55â kDa TrBgl2, solution NMR experiments demonstrated a specific binding site for the activator. A partial assignment of the NMR spectrum gave the identity of the amino acids at this site, allowing a model for TrBgl2 activation to be built. The activator binds at the entrance of the substrate-binding site, generating a productive conformation for the enzyme-substrate complex.
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Ativadores de Enzimas/química , Proteínas Fúngicas/química , Hypocreales/química , beta-Glucosidase/química , Ressonância Magnética Nuclear BiomolecularRESUMO
In humans and other vertebrates pannexin protein family was discovered by homology to invertebrate gap junction proteins. Several biological functions were attributed to three vertebrate pannexins members. Six clinically significant independent variants of the PANX1 gene lead to human infertility and oocyte development defects, and the Arg217His variant was associated with pronounced symptoms of primary ovarian failure, severe intellectual disability, sensorineural hearing loss, and kyphosis. At the same time, only mild phenotypes were observed in Panx1 knockout mice. In addition, a passenger mutation was identified in a popular line of Panx1 knockout mice, questioning even those effects. Using CRISPR/Cas9, we created a new line of Panx1 knockout mice and a new line of mice with the clinically significant Panx1 substitution (Arg217His). In both cases, we observed no significant changes in mouse size, weight, or fertility. In addition, we attempted to reproduce a previous study on sleep/wake and locomotor activity functions in Panx1 knockout mice and found that previously reported effects were probably not caused by the Panx1 knockout itself. We consider that the pathological role of Arg217His substitution in Panx1, and some Panx1 functions in general calls for a re-evaluation.
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Conexinas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Conexinas/genética , Conexinas/fisiologia , Perda Auditiva Neurossensorial/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação de Sentido Incorreto/genética , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/fisiologia , Fenótipo , Sono/genéticaRESUMO
The interaction of multi-LacNAc (Galß1-4GlcNAc)-containing N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers with human galectin-1 (Gal-1) and the carbohydrate recognition domain (CRD) of human galectin-3 (Gal-3) was analyzed using NMR methods in addition to cryo-electron-microscopy and dynamic light scattering (DLS) experiments. The interaction with individual LacNAc-containing components of the polymer was studied for comparison purposes. For Gal-3 CRD, the NMR data suggest a canonical interaction of the individual small-molecule bi- and trivalent ligands with the lectin binding site and better affinity for the trivalent arrangement due to statistical effects. For the glycopolymers, the interaction was stronger, although no evidence for forming a large supramolecule was obtained. In contrast, for Gal-1, the results indicate the formation of large cross-linked supramolecules in the presence of multivalent LacNAc entities for both the individual building blocks and the polymers. Interestingly, the bivalent and trivalent presentation of LacNAc in the polymer did not produce such an increase, indicating that the multivalency provided by the polymer is sufficient for triggering an efficient binding between the glycopolymer and Gal-1. This hypothesis was further demonstrated by electron microscopy and DLS methods.
Assuntos
Proteínas Sanguíneas/química , Galectina 1/química , Galectinas/química , Metacrilatos/química , Polímeros/química , Acrilamidas/química , Acrilamidas/farmacologia , Sítios de Ligação/efeitos dos fármacos , Proteínas Sanguíneas/genética , Carboidratos/química , Microscopia Crioeletrônica , Galectina 1/genética , Galectinas/genética , Humanos , Ligantes , Metacrilatos/farmacologia , Polímeros/farmacologia , Ligação Proteica/efeitos dos fármacosRESUMO
The efficiency of biodiversity assessments and biomonitoring studies is commonly challenged by limitations in taxonomic identification and quantification approaches. In this study, we assessed the effects of different taxonomic and numerical resolutions on a range of community structure metrics in invertebrate compositional data sets from six regions distributed across North and South America. We specifically assessed the degree of similarity in the metrics (richness, equitability, beta diversity, heterogeneity in community composition and congruence) for data sets identified to a coarse resolution (usually family level) and the finest taxonomic resolution practical (usually genus level, sometimes species or morphospecies) and by presence-absence and relative abundance numerical resolutions. Spearman correlations showed highly significant and positive associations between univariate metrics (richness and equitability) calculated for coarse- and finest-resolution datasets. Procrustes analysis detected significant congruence between composition datasets. Higher correlation coefficients were found for datasets with the same numerical resolutions regardless of the taxonomic level (about 90%), while the correlations for comparisons across numerical resolutions were consistently lower. Our findings indicate that family-level resolution can be used as a surrogate of finer taxonomic resolutions to calculate a range of biodiversity metrics commonly used to describe invertebrate community structure patterns in New World freshwater wetlands without significant loss of information. However, conclusions on biodiversity patterns derived from datasets with different numerical resolutions should be critically considered in studies on wetland invertebrates.
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Subjective measures of well-being are increasingly seen by scholars and policy makers as valuable tools to assess quality of life. Hedonic accounts focus on people's experience of life in positive ways while eudaimonic accounts are concerned with realization of personal potential. However, to what extent do an "enjoyable" and a "flourishing" life overlap? Using an innovative clustering-and-projection technique (Self-Organized Map), the joint distributional patterns of multiple hedonic and eudaimonic well-being indicators were examined in a nationally representative longitudinal study of US adults (MIDUS). Results show that the two accounts largely converged with about 70% of the sample observations registering high/low scores in both well-being dimensions. However, the remaining 30% of respondents experienced divergent well-being levels. Association between these combined profiles and a series of socio-demographic characteristics and social stratification factors were investigated. Findings showed that chances of uniformly high well-being increase with age, while higher income, educational level, marriage, and being a female are linked to lesser probabilities of experiencing joint low well-being patterns. Experiencing a combination of high hedonic / low eudaimonic well-being was more frequent for less educated individuals, and men. Finally, the persistence over time of these combined well-being profiles was more frequent in case of convergent hedonic/eudaimonic levels. For divergent patterns we revealed substantial changes over a 10-year period with respondents registering low hedonic / high eudaimonic well-being at time t having greater chances of upward movement toward improved well-being compared to individuals who experienced high hedonic / low eudaimonic levels in the first time period.
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Human guanylate kinase (hGMPK) is the only known enzyme responsible for cellular GDP production, making it essential for cellular viability and proliferation. Moreover, hGMPK has been assigned a critical role in metabolic activation of antiviral and antineoplastic nucleoside-analog prodrugs. Given that hGMPK is indispensable for producing the nucleotide building blocks of DNA, RNA, and cGMP and that cancer cells possess elevated GTP levels, it is surprising that a detailed structural and functional characterization of hGMPK is lacking. Here, we present the first high-resolution structure of hGMPK in the apo form, determined with NMR spectroscopy. The structure revealed that hGMPK consists of three distinct regions designated as the LID, GMP-binding (GMP-BD), and CORE domains and is in an open configuration that is nucleotide binding-competent. We also demonstrate that nonsynonymous single-nucleotide variants (nsSNVs) of the hGMPK CORE domain distant from the nucleotide-binding site of this domain modulate enzymatic activity without significantly affecting hGMPK's structure. Finally, we show that knocking down the hGMPK gene in lung adenocarcinoma cell lines decreases cellular viability, proliferation, and clonogenic potential while not altering the proliferation of immortalized, noncancerous human peripheral airway cells. Taken together, our results provide an important step toward establishing hGMPK as a potential biomolecular target, from both an orthosteric (ligand-binding sites) and allosteric (location of CORE domain-located nsSNVs) standpoint.
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Guanilato Quinases/metabolismo , Regulação Alostérica , Animais , Linhagem Celular Tumoral , Cristalografia por Raios X , Guanilato Quinases/química , Guanilato Quinases/genética , Humanos , Cinética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Mutagênese Sítio-Dirigida , Ressonância Magnética Nuclear Biomolecular , Estrutura Terciária de Proteína , Interferência de RNA , RNA Interferente Pequeno , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificaçãoRESUMO
Phosphatidylinositol-transfer proteins (PITPs) are key regulators of lipid signaling in eukaryotic cells. These proteins both potentiate the activities of phosphatidylinositol (PtdIns) 4-OH kinases and help channel production of specific pools of phosphatidylinositol 4-phosphate (PtdIns(4)P) dedicated to specific biological outcomes. In this manner, PITPs represent a major contributor to the mechanisms by which the biological outcomes of phosphoinositide are diversified. The two-ligand priming model proposes that the engine by which Sec14-like PITPs potentiate PtdIns kinase activities is a heterotypic lipid-exchange cycle where PtdIns is a common exchange substrate among the Sec14-like PITP family, but the second exchange ligand varies with the PITP. A major prediction of this model is that second-exchangeable ligand identity will vary from PITP to PITP. To address the heterogeneity in the second exchange ligand for Sec14-like PITPs, we used structural, computational, and biochemical approaches to probe the diversities of the lipid-binding cavity microenvironments of the yeast Sec14-like PITPs. The collective data report that yeast Sec14-like PITP lipid-binding pockets indeed define diverse chemical microenvironments that translate into differential ligand-binding specificities across this protein family.