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DNA damage provokes mutations and cancer and results from external carcinogens or endogenous cellular processes. However, the intrinsic instigators of endogenous DNA damage are poorly understood. Here, we identify proteins that promote endogenous DNA damage when overproduced: the DNA "damage-up" proteins (DDPs). We discover a large network of DDPs in Escherichia coli and deconvolute them into six function clusters, demonstrating DDP mechanisms in three: reactive oxygen increase by transmembrane transporters, chromosome loss by replisome binding, and replication stalling by transcription factors. Their 284 human homologs are over-represented among known cancer drivers, and their RNAs in tumors predict heavy mutagenesis and a poor prognosis. Half of the tested human homologs promote DNA damage and mutation when overproduced in human cells, with DNA damage-elevating mechanisms like those in E. coli. Our work identifies networks of DDPs that provoke endogenous DNA damage and may reveal DNA damage-associated functions of many human known and newly implicated cancer-promoting proteins.
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Dano ao DNA/genética , Dano ao DNA/fisiologia , Reparo do DNA/fisiologia , Proteínas de Bactérias/metabolismo , Instabilidade Cromossômica/fisiologia , Replicação do DNA/fisiologia , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/metabolismo , Instabilidade Genômica , Humanos , Proteínas de Membrana Transportadoras/fisiologia , Mutagênese , Mutação , Fatores de Transcrição/metabolismoRESUMO
Monoamine insufficiency is suggested to be associated with depressive features such as sadness, anhedonia, insomnia, and cognitive dysfunction, but the mechanisms that cause it are unclear. We found that the acute-phase protein lipopolysaccharide-binding protein (LBP) inhibits monoamine biosynthesis by acting as an endogenous inhibitor of dopamine-ß-hydroxylase (DBH) and aromatic-L-amino-acid-decarboxylase (DDC). LBP expression was increased in individuals with depression and by diverse stress challenges in mice. LBP antibodies and LBP knockdown inhibited monoamine insufficiency and depression-like features in mice, which worsened with LBP overexpression or administration. Monoamine insufficiency and depression-like symptoms were not induced by stressful stimuli in LBP-deficient mice, further highlighting a role for LBP in stress-induced depression, and a peptide we designed that blocks LBP-DBH and LBP-DDC interactions showed anti-depression effects in mice. This study reveals an important role for LBP in regulating monoamine biosynthesis and suggests that targeting LBP may have potential as a treatment for some individuals with depression.
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Proteínas de Transporte , Depressão , Camundongos , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Fase Aguda/genética , Proteínas de Fase Aguda/metabolismo , Glicoproteínas de Membrana/metabolismo , AminasRESUMO
mRNA translation relies on identifying translation initiation sites (TISs) in mRNAs. Alternative TISs are prevalent across plant transcriptomes, but the mechanisms for their recognition are unclear. Using ribosome profiling and machine learning, we developed models for predicting alternative TISs in the tomato (Solanum lycopersicum). Distinct feature sets were predictive of AUG and nonAUG TISs in 5' untranslated regions and coding sequences, including a novel CU-rich sequence that promoted plant TIS activity, a translational enhancer found across dicots and monocots, and humans and viruses. Our results elucidate the mechanistic and evolutionary basis of TIS recognition, whereby cis-regulatory RNA signatures affect start site selection. The TIS prediction model provides global estimates of TISs to discover neglected protein-coding genes across plant genomes. The prevalence of cis-regulatory signatures across plant species, humans, and viruses suggests their broad and critical roles in reprogramming the translational landscape.
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Eucariotos , Iniciação Traducional da Cadeia Peptídica , Humanos , Iniciação Traducional da Cadeia Peptídica/genética , Eucariotos/genética , Plantas/genética , Regiões 5' não Traduzidas , RNA Mensageiro/genética , Códon de IniciaçãoRESUMO
Pharmacological activation of voltage-gated ion channels by ligands serves as the basis for therapy and mainly involves a classic gating mechanism that augments the native voltage-dependent open probability. Through structure-based virtual screening, we identified a new scaffold compound, Ebio1, serving as a potent and subtype-selective activator for the voltage-gated potassium channel KCNQ2 and featuring a new activation mechanism. Single-channel patch-clamp, cryogenic-electron microscopy and molecular dynamic simulations, along with chemical derivatives, reveal that Ebio1 engages the KCNQ2 activation by generating an extended channel gate with a larger conductance at the saturating voltage (+50 mV). This mechanism is different from the previously observed activation mechanism of ligands on voltage-gated ion channels. Ebio1 caused S6 helices from residues S303 and F305 to perform a twist-to-open movement, which was sufficient to open the KCNQ2 gate. Overall, our findings provide mechanistic insights into the activation of KCNQ2 channel by Ebio1 and lend support for KCNQ-related drug development.
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Ativação do Canal Iônico , Canal de Potássio KCNQ2 , Simulação de Dinâmica Molecular , Canal de Potássio KCNQ2/metabolismo , Canal de Potássio KCNQ2/química , Humanos , Ativação do Canal Iônico/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/química , Animais , Técnicas de Patch-Clamp , Microscopia Crioeletrônica , Células HEK293 , Relação Estrutura-AtividadeRESUMO
Diversity, a hallmark of G protein-coupled receptor (GPCR) signaling, partly stems from alternative splicing of a single gene generating more than one isoform for a receptor. Additionally, receptor responses to ligands can be attenuated by desensitization upon prolonged or repeated ligand exposure. Both phenomena have been demonstrated and exemplified by the deuterostome tachykinin signaling system, although the role of phosphorylation in desensitization remains a subject of debate. Here, we describe the signaling system for tachykinin-related peptides (TKRPs) in a protostome, mollusk Aplysia. We cloned the Aplysia TKRP precursor, which encodes three TKRPs (apTKRP-1, apTKRP-2a, and apTKRP-2b) containing the FXGXR-amide motif. In situ hybridization and immunohistochemistry showed predominant expression of TKRP mRNA and peptide in the cerebral ganglia. TKRPs and their posttranslational modifications were observed in extracts of central nervous system ganglia using mass spectrometry. We identified two Aplysia TKRP receptors (apTKRPRs), named apTKRPR-A and apTKRPR-B. These receptors are two isoforms generated through alternative splicing of the same gene and differ only in their intracellular C termini. Structure-activity relationship analysis of apTKRP-2b revealed that both C-terminal amidation and conserved residues of the ligand are critical for receptor activation. C-terminal truncates and mutants of apTKRPRs suggested that there is a C-terminal phosphorylation-independent desensitization for both receptors. Moreover, apTKRPR-B also exhibits phosphorylation-dependent desensitization through the phosphorylation of C-terminal Ser/Thr residues. This comprehensive characterization of the Aplysia TKRP signaling system underscores the evolutionary conservation of the TKRP and TK signaling systems, while highlighting the intricacies of receptor regulation through alternative splicing and differential desensitization mechanisms.
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YWHAZ encodes an adapter protein 14-3-3ζ, which is involved in many signaling pathways that control cellular proliferation, migration and differentiation. It has not been definitely correlated to any phenotype in OMIM. To investigate the role of YWHAZ gene in intellectual disability and global developmental delay, we conducted whole-exon sequencing in all of the available members from a large three-generation family and we discovered that a novel variant of the YWHAZ gene was associated with intellectual disability and global developmental delay. This variant is a missense mutation of YWHAZ, p.Lys49Asn/c.147A > T, which was found in all affected members but not found in other unaffected members. We also conducted computational modeling and knockdown/knockin with Drosophila to confirm the role of the YWHAZ variant in intellectual disability. Computational modeling showed that the binding energy was increased in the mutated protein combining with the ligand indicating that the c147A > T variation was a loss-of-function variant. Cognitive defects and mushroom body morphological abnormalities were observed in YWHAZ c.147A > T knockin flies. The YWHAZ knockdown flies also manifested serious cognitive defects with hyperactivity behaviors, which is consistent with the clinical features. Our clinical and experimental results consistently suggested that YWHAZ was a novel intellectual disability pathogenic gene.
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Deficiência Intelectual , Malformações do Sistema Nervoso , Criança , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/complicações , Proteínas 14-3-3/genética , Mutação de Sentido Incorreto , Encéfalo , Deficiências do Desenvolvimento/genética , Deficiências do Desenvolvimento/complicaçõesRESUMO
BACKGROUND: Pharmacotherapy provides an option for adults with overweight and obesity to reduce their bodyweight if lifestyle modifications fail. We summarised the latest evidence for the benefits and harms of weight-lowering drugs. METHODS: This systematic review and network meta-analysis included searches of PubMed, Embase, and Cochrane Library (CENTRAL) from inception to March 23, 2021, for randomised controlled trials of weight-lowering drugs in adults with overweight and obesity. We performed frequentist random-effect network meta-analyses to summarise the evidence and applied the Grading of Recommendations Assessment, Development, and Evaluation frameworks to rate the certainty of evidence, calculate the absolute effects, categorise interventions, and present the findings. The study was registered with PROSPERO, CRD 42021245678. FINDINGS: 14 605 citations were identified by our search, of which 132 eligible trials enrolled 48 209 participants. All drugs lowered bodyweight compared with lifestyle modification alone; all subsequent numbers refer to comparisons with lifestyle modification. High to moderate certainty evidence established phentermine-topiramate as the most effective in lowering weight (odds ratio [OR] of ≥5% weight reduction 8·02, 95% CI 5·24 to 12·27; mean difference [MD] of percentage bodyweight change -7·98, 95% CI -9·27 to -6·69) followed by GLP-1 receptor agonists (OR 6·33, 95% CI 5·00 to 8·00; MD -5·79, 95% CI -6·34 to -5·25). Naltrexone-bupropion (OR 2·69, 95% CI 2·10 to 3·44), phentermine-topiramate (2·40, 1·68 to 3·44), GLP-1 receptor agonists (2·22, 1·74 to 2·84), and orlistat (1·71, 1·42 to 2·05) were associated with increased adverse events leading to drug discontinuation. In a post-hoc analysis, semaglutide, a GLP-1 receptor agonist, showed substantially larger benefits than other drugs with a similar risk of adverse events as other drugs for both likelihood of weight loss of 5% or more (OR 9·82, 95% CI 7·09 to 13·61) and percentage bodyweight change (MD -11·40, 95% CI -12·51 to -10·29). INTERPRETATION: In adults with overweight and obesity, phentermine-topiramate and GLP-1 receptor agonists proved the best drugs in reducing weight; of the GLP-1 agonists, semaglutide might be the most effective. FUNDING: 1.3.5 Project for Disciplines of Excellence, West China Hospital, Sichuan University.
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Obesidade , Sobrepeso , Adulto , Humanos , Sobrepeso/tratamento farmacológico , Metanálise em Rede , Topiramato/uso terapêutico , Obesidade/tratamento farmacológico , Redução de Peso , Fentermina/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Radiation-induced enteritis, a significant concern in abdominal radiation therapy, is associated closely with gut microbiota dysbiosis. The mucus layer plays a pivotal role in preventing the translocation of commensal and pathogenic microbes. Although significant expression of REGγ in intestinal epithelial cells is well established, its role in modulating the mucus layer and gut microbiota remains unknown. The current study revealed notable changes in gut microorganisms and metabolites in irradiated mice lacking REGγ, as compared to wild-type mice. Concomitant with gut microbiota dysbiosis, REGγ deficiency facilitated the infiltration of neutrophils and macrophages, thereby exacerbating intestinal inflammation after irradiation. Furthermore, fluorescence in situ hybridization assays unveiled an augmented proximity of bacteria to intestinal epithelial cells in REGγ knockout mice after irradiation. Mechanistically, deficiency of REGγ led to diminished goblet cell populations and reduced expression of key goblet cell markers, Muc2 and Tff3, observed in both murine models, minigut organoid systems and human intestinal goblet cells, indicating the intrinsic role of REGγ within goblet cells. Interestingly, although administration of broad-spectrum antibiotics did not alter the goblet cell numbers or mucin 2 (MUC2) secretion, it effectively attenuated inflammation levels in the ileum of irradiated REGγ absent mice, bringing them down to the wild-type levels. Collectively, these findings highlight the contribution of REGγ in counteracting radiation-triggered microbial imbalances and cell-autonomous regulation of mucin secretion.
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Enterite , Microbioma Gastrointestinal , Células Caliciformes , Homeostase , Camundongos Knockout , Mucina-2 , Complexo de Endopeptidases do Proteassoma , Animais , Humanos , Camundongos , Disbiose/microbiologia , Disbiose/metabolismo , Enterite/microbiologia , Enterite/metabolismo , Enterite/patologia , Células Caliciformes/patologia , Células Caliciformes/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Camundongos Endogâmicos C57BL , Mucina-2/metabolismo , Proteínas Associadas a Pancreatite/metabolismo , Lesões por Radiação/metabolismo , Lesões por Radiação/microbiologia , Lesões por Radiação/patologia , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Lesões Experimentais por Radiação/microbiologia , Fator Trefoil-3/metabolismo , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Complexo de Endopeptidases do Proteassoma/efeitos da radiação , Autoantígenos/genética , Autoantígenos/metabolismo , Autoantígenos/efeitos da radiaçãoRESUMO
ConspectusBuckminsterfullerene, C60, was discovered through a prominent mass peak containing 60 atoms produced from laser vaporization of graphite, driven by Kroto's interest in understanding the formation mechanisms of carbon-containing molecules in space. Inspired by the geodesic dome-shaped architecture designed by Richard Buckminster Fuller, after whom the particle was named, C60 was found to have a football-shaped structure comprising 20 hexagons and 12 pentagons. It sparked worldwide interest in understanding this new carbon allotrope, resulting in the awarding of the Noble Prize in Chemistry to Smalley, Kroto, and Curl in 1996.Intrinsically, C60 is an exceptional species because of its high stability and electron-accepting ability and its structural tunability by decorating or substituting either on its exterior surface or interior hollow cavity. For example, metal-decorated fullerene complexes have found important applications ranging from superconductivity, nanoscale electronic devices, and organic photovoltaic cells to catalysis and biomedicine. Compared to the large body of studies on atoms and molecules encapsulated by C60, studies on the exteriorly modified fullerenes, i.e., exohedral fullerenes, are scarcer. Surprisingly, to date, uncertainty exists about a fundamental question: what is the preferable exterior binding site of different kinds of single atoms on the C60 surface?In recent years, we have developed an experimental protocol to synthesize the desired fullerene-metal clusters and to record their infrared spectra via messenger-tagged infrared multiple photon dissociation spectroscopy. With complementary quantum chemical calculations and molecular dynamics simulations, we determined that the most probable binding site of a metal, specifically a vanadium cation, on C60 is above a pentagonal center in an η5 fashion. We explored the bonding nature between C60 and V+ and revealed that the high thermal stability of this cluster originates from large orbital and electrostatic interactions. Through comparing the measured infrared spectra of [C60-Metal]+ with the observational Spitzer data of several fullerene-rich planetary nebulae, we proposed that the complexes formed by fullerene and cosmically abundant metals, for example, iron, are promising carriers of astronomical unidentified spectroscopic features. This opens the door for a real consideration of Kroto's 30-year-old hypothesis that complexes involving cosmically abundant elements and C60 exhibit strong charge-transfer bands, similar to those of certain unidentified astrophysical spectroscopic features. We compiled a VibFullerene database and extracted a set of vibrational frequencies and intensities for fullerene derivatives to facilitate their potential detection by the James Webb Space Telescope. In addition, we showed that upon infrared irradiation C60V+ can efficiently catalyze water splitting to generate H2. This finding is attributed to the novel geometric-electronic effects of C60, acting as "hydrogen shuttle" and "electron sponge", which illustrates the important role of carbon-based supports in single-atom catalysts. Our work not only unveils the basic structures and bonding nature of fullerene-metal clusters but also elucidates their potential importance in astrophysics, astrochemistry, and catalysis, showing the multifaceted character of this class of clusters. More exciting and interesting aspects of the fullerene-metal clusters, such as ultrafast charge-transfer dynamics between fullerene and metal and their relevance to designing hybrid fullerene-metal junctions for electronic devices, are awaiting exploration.
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Plant viruses with densely packed genomes employ noncanonical translational strategies to increase the coding capacity for viral function. However, the diverse translational strategies used make it challenging to define the full set of viral genes. Here, using tomato yellow leaf curl Thailand virus (TYLCTHV, genus Begomovirus) as a model system, we identified genes beyond the annotated gene sets by experimentally profiling in vivo translation initiation sites (TISs). We found that unanticipated AUG TISs were prevalent and determined that their usage involves alternative transcriptional and/or translational start sites and is associated with flanking mRNA sequences. Specifically, two downstream in-frame TISs were identified in the viral gene AV2. These TISs were conserved in the begomovirus lineage and led to the translation of different protein isoforms localized to cytoplasmic puncta and at the cell periphery, respectively. In addition, we found translational evidence of an unexplored gene, BV2. BV2 is conserved among TYLCTHV isolates and localizes to the endoplasmic reticulum and plasmodesmata. Mutations of AV2 isoforms and BV2 significantly attenuated disease symptoms in tomato (Solanum lycopersicum). In conclusion, our study pinpointing in vivo TISs untangles the coding complexity of a plant viral genome and, more importantly, illustrates the biological significance of the hidden open-reading frames encoding viral factors for pathogenicity.
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Begomovirus , Solanum lycopersicum , Begomovirus/genética , Genoma Viral , Solanum lycopersicum/genética , Fases de Leitura Aberta/genética , Filogenia , Doenças das Plantas/genéticaRESUMO
The efficacy of electrical stimulation facilitating peripheral nerve regeneration is evidenced extensively, while the associated secondary damage resulting from repeated electrode invasion and indiscriminate stimulation is inevitable. Here, we present an optogenetics strategy that utilizes upconversion nanoparticles (UCNPs) to convert deeply penetrating near-infrared excitation into blue emission, which activates an adeno-associated virus-encoding ChR2 photoresponsive ion channel on cell membranes. The induced Ca2+ flux, similar to the ion flux in the electrical stimulation approach, efficiently regulates viability and proliferation, secretion of nerve growth factor, and neural function of RSC96 cells. Furthermore, deep near-infrared excitation is harnessed to stimulate autologous Schwann cells in situ via a UCNP-composited scaffold, which enhances nerve sprouting and myelination, consequently promoting functional recovery, electrophysiological restoration, and reinnervation of damaged nerves. This developed postoperatively noninvasive optogenetics strategy presents a novel, minimally traumatic, and enduring therapeutic stimulus to effectively promote peripheral nerve repair.
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Nanopartículas , Regeneração Nervosa , Optogenética , Células de Schwann , Nervo Isquiático , Animais , Optogenética/métodos , Nanopartículas/química , Ratos , Dependovirus/genética , Linhagem Celular , Traumatismos dos Nervos Periféricos/terapiaRESUMO
Chromatin connects DNA damage response factors to sites of damaged DNA to promote the signaling and repair of DNA lesions. The histone H2A variants H2AX, H2AZ, and macroH2A represent key chromatin constituents that facilitate DNA repair. Through proteomic screening of these variants, we identified ZMYM3 (zinc finger, myeloproliferative, and mental retardation-type 3) as a chromatin-interacting protein that promotes DNA repair by homologous recombination (HR). ZMYM3 is recruited to DNA double-strand breaks through bivalent interactions with both histone and DNA components of the nucleosome. We show that ZMYM3 links the HR factor BRCA1 to damaged chromatin through specific interactions with components of the BRCA1-A subcomplex, including ABRA1 and RAP80. By regulating ABRA1 recruitment to damaged chromatin, ZMYM3 facilitates the fine-tuning of BRCA1 interactions with DNA damage sites and chromatin. Consistent with a role in regulating BRCA1 function, ZMYM3 deficiency results in impaired HR repair and genome instability. Thus, our work identifies a critical chromatin-binding DNA damage response factor, ZMYM3, which modulates BRCA1 functions within chromatin to ensure the maintenance of genome integrity.
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Proteína BRCA1/metabolismo , Neoplasias Ósseas/metabolismo , Cromatina/metabolismo , Reparo do DNA , Proteínas Nucleares/metabolismo , Osteossarcoma/metabolismo , Sequência de Aminoácidos , Proteína BRCA1/genética , Neoplasias Ósseas/genética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Cromatina/genética , Quebras de DNA de Cadeia Dupla , Proteínas de Ligação a DNA , Instabilidade Genômica , Células HEK293 , Chaperonas de Histonas , Histonas/genética , Histonas/metabolismo , Recombinação Homóloga , Humanos , Proteínas Nucleares/genética , Osteossarcoma/genética , Homologia de Sequência de Aminoácidos , Células Tumorais CultivadasRESUMO
Cell mechanics are pivotal in regulating cellular activities, diseases progression, and cancer development. However, the understanding of how cellular viscoelastic properties vary in physiological and pathological stimuli remains scarce. Here, we develop a hybrid self-similar hierarchical theory-microrheology approach to accurately and efficiently characterize cellular viscoelasticity. Focusing on two key cell types associated with livers fibrosis-the capillarized liver sinusoidal endothelial cells and activated hepatic stellate cells-we uncover a universal two-stage power-law rheology characterized by two distinct exponents, αshort and αlong. The mechanical profiles derived from both exponents exhibit significant potential for discriminating among diverse cells. This finding suggests a potential common dynamic creep characteristic across biological systems, extending our earlier observations in soft tissues. Using a tailored hierarchical model for cellular mechanical structures, we discern significant variations in the viscoelastic properties and their distribution profiles across different cell types and states from the cytoplasm (elastic stiffness E1 and viscosity η), to a single cytoskeleton fiber (elastic stiffness E2), and then to the cell level (transverse expansion stiffness E3). Importantly, we construct a logistic-regression-based machine-learning model using the dynamic parameters that outperforms conventional cell-stiffness-based classifiers in assessing cell states, achieving an area under the curve of 97% vs. 78%. Our findings not only advance a robust framework for monitoring intricate cell dynamics but also highlight the crucial role of cellular viscoelasticity in discerning cell states across a spectrum of liver diseases and prognosis, offering new avenues for developing diagnostic and therapeutic strategies based on cellular viscoelasticity.
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Elasticidade , Viscosidade , Fenômenos Biomecânicos , Animais , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Células Estreladas do Fígado/citologia , Células Estreladas do Fígado/metabolismo , Reologia , Humanos , Modelos Biológicos , Fígado/citologia , Aprendizado de MáquinaRESUMO
BACKGROUND: Firmiana danxiaensis is a critically endangered and ecologically important tree currently only found in four locations in Danxia or Karst habitats in northern Guangdong Province, China. The specialized habitat preference makes it an ideal model species for study of adaptive evolution. Meanwhile, the phylogenetic relationships of F. danxiaensis in four locations under two landforms are unclear. Therefore, we sequenced its complete chloroplast (cp.) genomes and conducted comprehensive interspecific and intrageneric plastome studies. RESULTS: The F. danxiaensis plastomes in four locations showed a typical quadripartite and circular structure that ranged from 160,832 to 161,206 bp in size, with 112 unique genes encoded. Comparative genomics showed that the plastomes of F. danxiaensis were relatively conserved with high similarity of genome organization, gene number, GC content and SSRs. While the genomes revealed higher biased codon preferences in Karst habitat than those in Danxia habitats. Eighteen and 11 divergent hotpots were identified at interspecific and intrageneric levels for species identification and further phylogenetic studies. Seven genes (clpP, accD, ccsA, ndhH, rpl20, rpoC2, and rps4) were under positive selection and may be related to adaptation. Phylogenetic analysis revealed that F. danxiaensis is sister to F. major and F. simplex. However, the interspecific relationships are not consistent with the habitat types. CONCLUSIONS: The characteristics and interspecific relationship of F. danxiaensis plastomes provide new insights into further integration of geographical factors, environmental factors, and genetic variations on the genomic study of F. danxiaensis. Together, our study will contribute to the study of species identification, population genetics, and conservation biology of F. danxiaensis.
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Genoma de Cloroplastos , Filogenia , Genoma de Cloroplastos/genética , Genômica , Sequência de Bases , Genética PopulacionalRESUMO
It is increasingly clear that unconscious information impairs the performance of the corresponding action when the instruction to act is delayed. However, whether this impairment occurs at the response level or at the perceptual level remains controversial. This study used fMRI and a computational model with a pre-post design to address this elusive issue. The fMRI results showed that when the unconscious information containing strong stimulus-response associations was irrelevant to subsequent stimuli, the precuneus in the parietal lobe, which is thought to be involved in sensorimotor processing, was activated. In contrast, when the unconscious information was relevant to subsequent stimuli, regardless of the strength of the stimulus-response associations, some regions in the occipital and temporal cortices, which are thought to be involved in visual perceptual processing, were activated. In addition, the percent signal change in the regions of interest associated with motor inhibition was modulated by compatibility in the irrelevant but not in the relevant stimuli conditions. Modeling of behavioral data further supported that the irrelevant and relevant stimuli conditions involved fundamentally different mechanisms. Our finding reconciles the debate about the mechanism by which unconscious information impairs action performance and has important implications for understanding of unconscious cognition.
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Imageamento por Ressonância Magnética , Desempenho Psicomotor , Inconsciente Psicológico , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Desempenho Psicomotor/fisiologia , Simulação por Computador , Mapeamento Encefálico/métodos , Encéfalo/fisiologia , Encéfalo/diagnóstico por imagem , Modelos NeurológicosRESUMO
Sulfate crystals are often criticized for their low birefringence. The small anisotropic SO4 group is becoming the biggest bottleneck hindering the application of sulfates in optical functional materials. In this study, we report a new method to significantly enhance the birefringence of sulfates. The title compound increases the birefringence recording of sulfates to 0.542@546 nm, which is significantly larger than that of the commercial birefringent crystal of TiO2 (0.306@546.1 nm). At the infrared wavelength, the birefringence of Hg4(Te2O5)(SO4) can be up to 0.400@1064 nm, which is also much larger than the infrared birefringent crystal of YVO4 (0.209@1064 nm). In addition, it also has a wide transparency range, high thermal stability, and excellent environmental stability, making it a potential birefringent material. Hg4(Te2O5)(SO4) features a novel two-dimensional layered structure composed of [Hg4(Te2O5)]2+ layers separated by isolated (SO4)2- tetrahedra. This compound was designed by introducing a highly selective cation in a tellurite sulfate system. The low valence low coordination cations connect with tellurite groups only, making the sulfate isolated in the structure. The steric repulsive action of the isolated SO4 tetrahedra may regulate the linear and lone pair groups arranged in a way that favors large birefringence. This method can be proven by theoretical calculations. PAWED studies showed that the large birefringence originated from the synergistic effect of (Hg2O2)2-, (Te2O5)2-, and (SO4)2- units, with a contribution ratio of 42.17, 37.92, and 19.88%, respectively. Our work breaks the limitation of low birefringence in sulfates and opens up new possibilities for their application as birefringent crystals.
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Understanding single-molecule multivalent ligand-receptor interactions is crucial for comprehending molecular recognition at biological interfaces. However, label-free identifications of these transient interactions during multistep binding processes remains challenging. Herein, we introduce a ligand-receptor-anchored nanopore that allows the protein to maintain structural flexibility and favorable orientations in native states, mapping dynamic multivalent interactions. Using a four-state Markov chain model, we clarify two concentration-dependent binding pathways for the Omicron spike protein (Omicron S) and soluble angiotensin-converting enzyme 2 (sACE2): sequential and concurrent. Real-time kinetic analysis at the single-monomeric subunit level reveals that three S1 monomers of Omicron S exhibit a consistent and robust binding affinity toward sACE2 (-13.1 ± 0.2 kcal/mol). These results highlight the enhanced infectivity of Omicron S compared to other homologous spike proteins (WT S and Delta S). Notably, the preceding binding of sACE2 to Omicron S facilitates the subsequent binding steps, which was previously obscured in bulk measurements. Our single-molecule studies resolve the controversy over the disparity between the measured spike protein binding affinity with sACE2 and the viral infectivity, offering valuable insights for drug design and therapies.
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The standout characteristic of the orchid perianth is the transformation of the upper median petal into a distinctively formed lip, which gives orchid flowers their typically zygomorphic symmetry and makes them the most popular ornamental plants worldwide. To study orchid flower development, two WUSCHEL-related homeobox (WOX) genes, PaWOX3 and PaWOX3B, were identified in Phalaenopsis. PaWOX3 and PaWOX3B mRNAs accumulate abundantly during early reproductive development and perianths of young buds, significantly decrease in mature flower and absent in vegetative leaves and roots. PaWOX3 and PaWOX3B virus-induced gene silencing (VIGS) knockdown in Phalaenopsis significantly reduces floral bud numbers, suggesting that PaWOX3/PaWOX3B may be involved in flower initiation. Transgenic Arabidopsis ectopically expressing repressor forms of PaWOX3/PaWOX3B and their Oncidium orthologue, OnPRS, exhibit lateral organ development defects, implicating these genes likely have function in regulating growth and differentiation for lateral organs. Neither PaWOX3, PaWOX3B single nor PaWOX3/PaWOX3B double VIGS Phalaenopsis altered the flower morphology. Interestingly, double silencing of PaWOX3 or PaWOX3B with OAGL6-2, which controlled the identity/formation of lips, altered the symmetry of 'BigLip' produced in OAGL6-2 VIGS. This result indicated that the levels of PaWOX3/PaWOX3B are still sufficient to maintain the symmetry for the OAGL6-2 VIGS 'BigLip'. However, the symmetry of the OAGL6-2 VIGS 'BigLip' can not be maintained once the expression of PaWOX3 or PaWOX3B is further reduced. Thus, in addition to control lip identity, this study further found that OAGL6-2 could cooperate with functionally redundant PaWOX3/PaWOX3B in maintaining the symmetric axis of lip.
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Dual tasks (DTs) combining walking with a cognitive task can cause various levels of cognitive-motor interference, depending on which brain resources are recruited in each case. However, the brain activation and functional connectivity underlying cognitive-motor interferences remain to be elucidated. Therefore, this study investigated the neural correlation during different DT conditions in 40 healthy young adults (mean age: 27.53 years, 28 women). The DTs included walking during subtraction or N-Back tasks. Cognitive-motor interference was calculated, and brain activation and functional connectivity were analysed. Portable functional near-infrared spectroscopy was utilized to monitor haemodynamics in the prefrontal cortex (PFC), motor cortex and parietal cortex during each task. Walking interference (decrease in walking speed during DT) was greater than cognitive interference (decrease in cognitive performance during DT), regardless of the type of task. Brain activation in the bilateral PFC and parietal cortex was greater for walking during subtraction than for standing subtraction. Furthermore, brain activation was higher in the bilateral motor and parietal and PFCs for walking during subtraction than for walking alone, but only increased in the PFC for walking during N-Back. Coherence between the bilateral lateral PFC and between the left lateral PFC and left motor cortex was significantly greater for walking during 2-Back than for walking. The PFC, a critical brain region for organizing cognitive and motor functions, played a crucial role in integrating information coming from multiple brain networks required for completing DTs. Therefore, the PFC could be a potential target for the modulation and improvement of cognitive-motor functions during neurorehabilitation.
Assuntos
Cognição , Desempenho Psicomotor , Espectroscopia de Luz Próxima ao Infravermelho , Humanos , Feminino , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Masculino , Adulto , Cognição/fisiologia , Desempenho Psicomotor/fisiologia , Adulto Jovem , Caminhada/fisiologia , Córtex Motor/fisiologia , Córtex Pré-Frontal/fisiologia , Córtex Pré-Frontal/diagnóstico por imagem , Lobo Parietal/fisiologiaRESUMO
Limited treatment options and multidrug-resistant (MDR) Klebsiella pneumoniae present a significant therapeutic challenge, underscoring the need for novel approaches. Drug repurposing is a promising tool for augmenting the activity of many antibiotics. This study aimed to identify novel synergistic drug combinations against K. pneumoniae based on drug repurposing. We used the clinically isolated GN 172867 MDR strain of K. pneumoniae to determine the reversal resistance activity of zidovudine (AZT). The combined effects of AZT and various antibiotics, including nitrofurantoin (NIT) and omadacycline (OMC), were examined using the checkerboard method, growth curves, and crystal violet assays to assess biofilms. An in vitro combination activity testing was carried out in 12 isolates of K. pneumoniae. In vivo murine urinary tract and lung infection models were used to evaluate the therapeutic effects of AZT + NIT and AZT + OMC, respectively. The fractional inhibitory concentration index and growth curve demonstrated that AZT synergized with NIT or OMC against K. pneumoniae strains. In addition, AZT + NIT inhibited biofilm formation and cleared mature biofilms. In vivo, compared with untreated GN 172867-infected mice, AZT + NIT and AZT + OMC treatment decreased colony counts in multiple tissues (P < 0.05) and pathological scores in the bladder and kidneys (P < 0.05) and increased the survival rate by 60% (P < 0.05). This study evaluated the combination of AZT and antibiotics to treat drug-resistant K. pneumoniae infections and found novel drug combinations for the treatment of acute urinary tract infections. These findings suggest that AZT may exert significant anti-resistance activity.