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Among the five KCNQ channels, also known as the Kv7 voltage-gated potassium (Kv) channels, KCNQ2-KCNQ5 control neuronal excitability. Dysfunctions of KCNQ2-KCNQ5 are associated with neurological disorders such as epilepsy, deafness, and neuropathic pain. Here, we report the cryoelectron microscopy (cryo-EM) structures of human KCNQ4 and its complexes with the opener retigabine or the blocker linopirdine at overall resolutions of 2.5, 3.1, and 3.3 Å, respectively. In all structures, a phosphatidylinositol 4,5-bisphosphate (PIP2) molecule inserts its head group into a cavity within each voltage-sensing domain (VSD), revealing an unobserved binding mode for PIP2. Retigabine nestles in each fenestration, inducing local shifts. Instead of staying within the central pore, linopirdine resides in a cytosolic cavity underneath the inner gate. Electrophysiological analyses of various mutants corroborated the structural observations. Our studies reveal the molecular basis for the modulatory mechanism of neuronal KCNQ channels and provide a framework for structure-facilitated drug discovery targeting these important channels.
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Carbamatos/farmacologia , Indóis/farmacologia , Canais de Potássio KCNQ , Fenilenodiaminas/farmacologia , Piridinas/farmacologia , Animais , Microscopia Crioeletrônica , Humanos , Canais de Potássio KCNQ/agonistas , Canais de Potássio KCNQ/antagonistas & inibidores , Canais de Potássio KCNQ/genética , Canais de Potássio KCNQ/metabolismo , Mutação , Fosfatidilinositol 4,5-Difosfato/metabolismo , Domínios Proteicos , Células Sf9 , SpodopteraRESUMO
Missing heritability in genome-wide association studies defines a major problem in genetic analyses of complex biological traits1,2. The solution to this problem is to identify all causal genetic variants and to measure their individual contributions3,4. Here we report a graph pangenome of tomato constructed by precisely cataloguing more than 19 million variants from 838 genomes, including 32 new reference-level genome assemblies. This graph pangenome was used for genome-wide association study analyses and heritability estimation of 20,323 gene-expression and metabolite traits. The average estimated trait heritability is 0.41 compared with 0.33 when using the single linear reference genome. This 24% increase in estimated heritability is largely due to resolving incomplete linkage disequilibrium through the inclusion of additional causal structural variants identified using the graph pangenome. Moreover, by resolving allelic and locus heterogeneity, structural variants improve the power to identify genetic factors underlying agronomically important traits leading to, for example, the identification of two new genes potentially contributing to soluble solid content. The newly identified structural variants will facilitate genetic improvement of tomato through both marker-assisted selection and genomic selection. Our study advances the understanding of the heritability of complex traits and demonstrates the power of the graph pangenome in crop breeding.
Assuntos
Variação Genética , Genoma de Planta , Estudo de Associação Genômica Ampla , Melhoramento Vegetal , Solanum lycopersicum , Alelos , Produtos Agrícolas/genética , Genoma de Planta/genética , Desequilíbrio de Ligação , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismoRESUMO
Despite the widespread use of ionizable lipid nanoparticles (LNPs) in clinical applications for messenger RNA (mRNA) delivery, the mRNA drug delivery system faces an efficient challenge in the screening of LNPs. Traditional screening methods often require a substantial amount of experimental time and incur high research and development costs. To accelerate the early development stage of LNPs, we propose TransLNP, a transformer-based transfection prediction model designed to aid in the selection of LNPs for mRNA drug delivery systems. TransLNP uses two types of molecular information to perceive the relationship between structure and transfection efficiency: coarse-grained atomic sequence information and fine-grained atomic spatial relationship information. Due to the scarcity of existing LNPs experimental data, we find that pretraining the molecular model is crucial for better understanding the task of predicting LNPs properties, which is achieved through reconstructing atomic 3D coordinates and masking atom predictions. In addition, the issue of data imbalance is particularly prominent in the real-world exploration of LNPs. We introduce the BalMol block to solve this problem by smoothing the distribution of labels and molecular features. Our approach outperforms state-of-the-art works in transfection property prediction under both random and scaffold data splitting. Additionally, we establish a relationship between molecular structural similarity and transfection differences, selecting 4267 pairs of molecular transfection cliffs, which are pairs of molecules that exhibit high structural similarity but significant differences in transfection efficiency, thereby revealing the primary source of prediction errors. The code, model and data are made publicly available at https://github.com/wklix/TransLNP.
Assuntos
Lipídeos , Lipossomos , Nanopartículas , RNA Mensageiro , Nanopartículas/química , RNA Mensageiro/genética , RNA Mensageiro/química , Lipídeos/química , Transfecção , Humanos , Modelos Moleculares , Sistemas de Liberação de MedicamentosRESUMO
As an oocyte-specific growth factor, bone morphogenetic protein 15 (BMP15) plays a critical role in controlling folliculogenesis. However, the mechanism of BMP15 action remains elusive. Using zebrafish as the model, we created a bmp15 mutant using CRISPR/Cas9 and demonstrated that bmp15 deficiency caused a significant delay in follicle activation and puberty onset followed by a complete arrest of follicle development at previtellogenic (PV) stage without yolk accumulation. The mutant females eventually underwent female-to-male sex reversal to become functional males, which was accompanied by a series of changes in secondary sexual characteristics. Interestingly, the blockade of folliculogenesis and sex reversal in bmp15 mutant could be partially rescued by the loss of inhibin (inha-/-). The follicles of double mutant (bmp15-/-;inha-/-) could progress to mid-vitellogenic (MV) stage with yolk accumulation and the fish maintained their femaleness without sex reversal. Transcriptome analysis revealed up-regulation of pathways related to TGF-ß signaling and endocytosis in the double mutant follicles. Interestingly, the expression of inhibin/activin ßAa subunit (inhbaa) increased significantly in the double mutant ovary. Further knockout of inhbaa in the triple mutant (bmp15-/-;inha-/-;inhbaa-/-) resulted in the loss of yolk granules again. The serum levels of estradiol (E2) and vitellogenin (Vtg) both decreased significantly in bmp15 single mutant females (bmp15-/-), returned to normal in the double mutant (bmp15-/-;inha-/-), but reduced again significantly in the triple mutant (bmp15-/-;inha-/-;inhbaa-/-). E2 treatment could rescue the arrested follicles in bmp15-/-, and fadrozole (a nonsteroidal aromatase inhibitor) treatment blocked yolk accumulation in bmp15-/-;inha-/- fish. The loss of inhbaa also caused a reduction of Vtg receptor-like molecules (e.g., lrp1ab and lrp2a). In summary, the present study provided comprehensive genetic evidence that Bmp15 acts together with the activin-inhibin system in the follicle to control E2 production from the follicle, Vtg biosynthesis in the liver and its uptake by the developing oocytes.
Assuntos
Proteína Morfogenética Óssea 15 , Inibinas , Proteínas de Peixe-Zebra , Peixe-Zebra , Animais , Feminino , Masculino , Ativinas/genética , Proteína Morfogenética Óssea 15/genética , Proteína Morfogenética Óssea 15/metabolismo , Inibinas/genética , Inibinas/metabolismo , Mutação , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismoRESUMO
In recent years, accumulating evidence has demonstrated the role of long noncoding RNAs (lncRNAs) in colon cancer. We aim to investigate the role of MIR143HG, also known as CARMN (Cardiac mesoderm enhancer-associated noncoding RNA) in colon cancer and explore the related mechanisms. An RNAseq data analysis was performed to screen differentially expressed lncRNAs associated with colon cancer. Next, MIR143HG expression was quantified in colon cancer cells. Moreover, the contributory roles of MIR143HG in the progression of colon cancer with the involvement of DNMT1 and HOXB7 (Homeobox B7) were evaluated after restored MIR143HG or depleted HOXB7. Finally, the effects of MIR143HG were investigated in vivo by measuring tumor formation in nude mice. High-throughput transcriptome sequencing was employed to validate the specific mechanisms by which MIR143HG and HOXB7 affect tumor growth in vivo. MIR143HG was found to be poorly expressed, while HOXB7 was highly expressed in colon cancer. MIR143HG could promote HOXB7 methylation by recruiting DNMT1 to reduce HOXB7 expression. Upregulation of MIR143HG or downregulation of HOXB7 inhibited cell proliferation, invasion and migration and facilitated apoptosis in colon cancer cells so as to delay the progression of colon cancer. The same trend was identified in vivo. Our study provides evidence that restoration of MIR143HG suppressed the progression of colon cancer via downregulation of HOXB7 through DNMT1-mediated HOXB7 promoter methylation. Thus, MIR143HG may be a potential candidate for the treatment of colon cancer.
Assuntos
Neoplasias do Colo , DNA (Citosina-5-)-Metiltransferase 1 , Proteínas de Homeodomínio , RNA Longo não Codificante , Animais , Camundongos , Neoplasias do Colo/genética , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Proteínas de Homeodomínio/genética , Metilação , Metiltransferases , Camundongos Nus , Regiões Promotoras Genéticas , RNA Longo não Codificante/genética , Fatores de Transcrição , HumanosRESUMO
Among the ten subtypes of mammalian voltage-gated calcium (Cav) channels, Cav3.1-Cav3.3 constitute the T-type, or the low-voltage-activated, subfamily, the abnormal activities of which are associated with epilepsy, psychiatric disorders and pain1-5. Here we report the cryo-electron microscopy structures of human Cav3.1 alone and in complex with a highly Cav3-selective blocker, Z9446,7, at resolutions of 3.3 Å and 3.1 Å, respectively. The arch-shaped Z944 molecule reclines in the central cavity of the pore domain, with the wide end inserting into the fenestration on the interface between repeats II and III, and the narrow end hanging above the intracellular gate like a plug. The structures provide the framework for comparative investigation of the distinct channel properties of different Cav subfamilies.
Assuntos
Apoproteínas/química , Apoproteínas/ultraestrutura , Bloqueadores dos Canais de Cálcio/química , Canais de Cálcio Tipo T/química , Canais de Cálcio Tipo T/ultraestrutura , Microscopia Crioeletrônica , Piperidinas/química , Regulação Alostérica/efeitos dos fármacos , Motivos de Aminoácidos , Sequência de Aminoácidos , Apoproteínas/genética , Sítios de Ligação , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo T/genética , Humanos , Modelos Moleculares , Piperidinas/farmacologia , Ligação Proteica , Conformação Proteica , Deleção de SequênciaRESUMO
Activin and inhibin are both dimeric proteins sharing the same ß subunits that belong to the TGF-ß superfamily. They are well known for stimulating and inhibiting pituitary FSH secretion, respectively, in mammals. In addition, activin also acts as a mesoderm-inducing factor in frogs. However, their functions in development and reproduction of other species are poorly defined. In this study, we disrupted all three activin/inhibin ß subunits (ßAa, inhbaa; ßAb, inhbab; and ßB, inhbb) in zebrafish using CRISPR/Cas9. The loss of ßAa/b but not ßB led to a high mortality rate in the post-hatching stage. Surprisingly, the expression of fshb but not lhb in the pituitary increased in the female ßA mutant together with aromatase (cyp19a1a) in the ovary. The single mutant of ßAa/b showed normal folliculogenesis in young females; however, their double mutant (inhbaa-/-;inhbab-/-) showed delayed follicle activation, granulosa cell hypertrophy, stromal cell accumulation and tissue fibrosis. The ovary of inhbaa-/- deteriorated progressively after 180 dpf with reduced fecundity and the folliculogenesis ceased completely around 540 dpf. In addition, tumor- or cyst-like tissues started to appear in the inhbaa-/- ovary after about one year. In contrast to females, activin ßAa/b mutant males showed normal spermatogenesis and fertility. As for activin ßB subunit, the inhbb-/- mutant exhibited normal folliculogenesis, spermatogenesis and fertility in both sexes; however, the fecundity of mutant females decreased dramatically at 270 dpf with accumulation of early follicles. In summary, the activin-inhibin system plays an indispensable role in fish reproduction, in particular folliculogenesis and ovarian homeostasis.
Assuntos
Subunidades beta de Inibinas , Inibinas , Animais , Feminino , Inibinas/genética , Inibinas/metabolismo , Subunidades beta de Inibinas/genética , Subunidades beta de Inibinas/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Ativinas/genética , Ativinas/metabolismo , Reprodução/genética , Mamíferos/metabolismoRESUMO
Growth differentiation factor 9 (GDF9) was the first oocyte-specific growth factor identified; however, most information about GDF9 functions comes from studies in the mouse model. In this study, we created a mutant for Gdf9 gene (gdf9-/-) in zebrafish using TALEN approach. The loss of Gdf9 caused a complete arrest of follicle development at primary growth (PG) stage. These follicles eventually degenerated, and all mutant females gradually changed to males through sex reversal, which could be prevented by mutation of the male-promoting gene dmrt1. Interestingly, the phenotypes of gdf9-/- could be rescued by simultaneous mutation of inhibin α (inha-/-) but not estradiol treatment, suggesting a potential role for the activin-inhibin system or its signaling pathway in Gdf9 actions. In gdf9-null follicles, the expression of activin ßAa (inhbaa), but not ßAb (inhbab) and ßB (inhbb), decreased dramatically; however, its expression rebounded in the double mutant (gdf9-/-;inha-/-). These results indicate clearly that the activation of PG follicles to enter the secondary growth (SG) requires intrinsic factors from the oocyte, such as Gdf9, which in turn works on the neighboring follicle cells to trigger follicle activation, probably involving activins. In addition, our data also support the view that estrogens are not involved in follicle activation as recently reported.
Assuntos
Fator 9 de Diferenciação de Crescimento , Peixe-Zebra , Camundongos , Feminino , Animais , Masculino , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Fator 9 de Diferenciação de Crescimento/genética , Fator 9 de Diferenciação de Crescimento/metabolismo , Inibinas/genética , Inibinas/metabolismo , Folículo Ovariano/metabolismo , Ativinas/genética , Ativinas/metabolismoRESUMO
Drug combination therapy is generally more effective than monotherapy in the field of cancer treatment. However, screening for effective synergistic combinations from a wide range of drug combinations is particularly important given the increase in the number of available drug classes and potential drug-drug interactions. Existing methods for predicting the synergistic effects of drug combinations primarily focus on extracting structural features of drug molecules and cell lines, but neglect the interaction mechanisms between cell lines and drug combinations. Consequently, there is a deficiency in comprehensive understanding of the synergistic effects of drug combinations. To address this issue, we propose a drug combination synergy prediction model based on multi-source feature interaction learning, named MFSynDCP, aiming to predict the synergistic effects of anti-tumor drug combinations. This model includes a graph aggregation module with an adaptive attention mechanism for learning drug interactions and a multi-source feature interaction learning controller for managing information transfer between different data sources, accommodating both drug and cell line features. Comparative studies with benchmark datasets demonstrate MFSynDCP's superiority over existing methods. Additionally, its adaptive attention mechanism graph aggregation module identifies drug chemical substructures crucial to the synergy mechanism. Overall, MFSynDCP is a robust tool for predicting synergistic drug combinations. The source code is available from GitHub at https://github.com/kkioplkg/MFSynDCP .
Assuntos
Benchmarking , Treinamento por Simulação , Combinação de Medicamentos , Quimioterapia Combinada , Linhagem CelularRESUMO
Accurate assessment of epidermal growth factor receptor (EGFR) mutation status and subtype is critical for the treatment of non-small cell lung cancer patients. Conventional molecular testing methods for detecting EGFR mutations have limitations. In this study, an artificial intelligence-powered deep learning framework was developed for the weakly supervised prediction of EGFR mutations in non-small cell lung cancer from hematoxylin and eosin-stained histopathology whole-slide images. The study cohort was partitioned into training and validation subsets. Foreground regions containing tumor tissue were extracted from whole-slide images. A convolutional neural network employing a contrastive learning paradigm was implemented to extract patch-level morphologic features. These features were aggregated using a vision transformer-based model to predict EGFR mutation status and classify patient cases. The established prediction model was validated on unseen data sets. In internal validation with a cohort from the University of Science and Technology of China (n = 172), the model achieved patient-level areas under the receiver-operating characteristic curve (AUCs) of 0.927 and 0.907, sensitivities of 81.6% and 83.3%, and specificities of 93.0% and 92.3%, for surgical resection and biopsy specimens, respectively, in EGFR mutation subtype prediction. External validation with cohorts from the Second Affiliated Hospital of Anhui Medical University and the First Affiliated Hospital of Wannan Medical College (n = 193) yielded patient-level AUCs of 0.849 and 0.867, sensitivities of 79.2% and 80.7%, and specificities of 91.7% and 90.7% for surgical and biopsy specimens, respectively. Further validation with the Cancer Genome Atlas data set (n = 81) showed an AUC of 0.861, a sensitivity of 84.6%, and a specificity of 90.5%. Deep learning solutions demonstrate potential advantages for automated, noninvasive, fast, cost-effective, and accurate inference of EGFR alterations from histomorphology. Integration of such artificial intelligence frameworks into routine digital pathology workflows could augment existing molecular testing pipelines.
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Molecular-assisted breeding is an effective way to improve targeted agronomic traits. dep1 (dense and erect panicle 1) is a pleiotropic gene that regulates yield, quality, disease resistance, and stress tolerance, traits that are of great value in rice (Oryza sativa L.) breeding. In this study, a colorimetric LAMP (loop-mediated isothermal amplification) assay was developed for the detection of the dep1 allele and tested for the screening and selection of the heavy-panicle hybrid rice elite restorer line SHUHUI498, modified with the allele. InDel (Insertion and Deletion) primers (DEP1_F and DEP1_R) and LAMP primers (F3, B3, FIP, and BIP) for genotyping were designed using the Primer3 Plus (version 3.3.0) and PrimerExplore (version 5) software. Our results showed that both InDel and LAMP markers could be used for accurate genotyping. After incubation at a constant temperature of 65 °C for 60 min with hydroxynaphthol blue (HNB) as a color indicator, the color of the LAMP assay containing the dep1 allele changed to sky blue. The SHUHUI498 rice line that was detected in our LAMP assay displayed phenotypes consistent with the dep1 allele such as having a more compact plant architecture, straight stems and leaves, and a significant increase in the number of effective panicles and spikelets, demonstrating the effectiveness of our method in screening for the dep1 allele in rice breeding.
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Acute myeloid leukemia (AML) is a highly heterogeneous disease. Exploring the pathogenesis of AML is still an important topic in the treatment of AML. The expression levels of miR-26b-5p and USP48 were measured by qRT-PCR. The expression levels of related proteins were detected by Western blot. Cell proliferation and apoptosis were detected by CCK-8 and flow cytometry, respectively. Coimmunoprecipitation was used to examine the interaction between USP48 and Wnt5a. Bioinformatics analysis showed that high levels of miR-26b-5p and low levels of USP48 were associated with poor prognosis in AML. miR-26b-5p can negatively regulate the expression of USP48. Downregulation of miR-26b-5p inhibited EMT, cell viability and proliferation of AML cells and accelerated apoptosis. Furthermore, the influence of miR-26b-5p inhibition and USP48 knockdown on AML progression could be reversed by a Wnt/ß-catenin signaling pathway inhibitor. This study revealed that miR-26b-5p regulates AML progression, possibly by targeting the USP48-mediated Wnt/ß-catenin molecular axis to affect AML cell biological behavior.
Assuntos
Leucemia Mieloide Aguda , MicroRNAs , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Via de Sinalização Wnt/genética , beta Catenina/genética , Western Blotting , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Proliferação de Células/genética , Linhagem Celular Tumoral , Apoptose/genética , Proteases Específicas de Ubiquitina/metabolismoRESUMO
The urinary tract is constantly exposed to microorganisms. Host defense mechanisms in protection from microbial colonization and development of urinary tract infections require better understanding to control kidney infection. Here we report that the lectin collectin 11 (CL-11), particularly kidney produced, has a pivotal role in host defense against uropathogen infection. CL-11 was found in mouse urine under normal and pathological conditions. Mice with global gene ablation of Colec11 had increased susceptibility to and severity of kidney and to an extent, bladder infection. Mice with kidney-specific Colec11 ablation exhibited a similar disease phenotype to that observed in global Colec11 deficient mice, indicating the importance of kidney produced CL-11 for protection against kidney and bladder infection. Conversely, intravesical or systemic administration of recombinant CL-11 reduced susceptibility to and severity of kidney and bladder infection. Mechanism analysis revealed that CL-11 can mediate several key innate defense mechanisms (agglutination, anti- adhesion, opsonophagocytosis), and limit local inflammatory responses to pathogens. Furthermore, CL-11-mediated innate defense mechanisms can act on clinically relevant microorganisms including multiple antibiotic resistant strains. CL-11 was detectable in eight of 24 urine samples from patients with urinary tract infections but not detectable in urine samples from ten healthy individuals. Thus, our findings demonstrate that CL-11 is a key factor of host defense mechanisms in kidney and bladder infection with therapeutic potential for human application.
Assuntos
Cistite , Infecções por Escherichia coli , Infecções Urinárias , Humanos , Camundongos , Animais , Bexiga Urinária , Rim , Colectinas/genéticaRESUMO
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant is becoming a dominant circulator and has several mutations in the spike glycoprotein, which may cause shifts of immunogenicity, so as to result in immune escape and breakthrough infection among the already infected or vaccinated populations. It is unclear whether infection with Omicron could generate adequate cross-variant protection. To investigate this possibility, we used Syrian hamsters as an animal model for infection of SARS-CoV-2. The serum from Omicron BA.1 variant-infected hamsters showed a significantly lower neutralization effect against infection of the same or different SARS-CoV-2 variants than the serum from Beta variant-infected hamsters. Furthermore, the serum from Omicron BA.1 variant-infected hamsters were insufficient to protect against rechallenge of SARS-CoV-2 Prototype, Beta and Delta variants and itself. Importantly, we found that rechallenge with different SARS-CoV-2 lineages elevated cross-variant serum neutralization titers. Overall, our findings indicate a weakened immunogenicity feature of Omicron BA.1 variant that can be overcome by rechallenge of a different SARS-CoV-2 lineages. Our results may lead to a new guideline in generation and use of the vaccinations to combat the pandemic of SARS-CoV-2 Omicron variant and possible new variants. IMPORTANCE The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant causes breakthrough infections among convalescent patients and vaccinated populations. However, Omicron does not generate robust cross-protective responses. Here, we investigate whether heterologous SARS-CoV-2 challenge is able to enhance antibody response in a sensitive animal model, namely, Syrian hamster. Of note, a heterologous challenge of Beta and Omicron BA.1 variant significantly broadens the breadth of SARS-CoV-2 neutralizing responses against the prototype, Beta, Delta, and Omicron BA.1 variants. Our findings confirm that vaccination strategy with heterologous antigens might be a good option to protect against the evolving SARS-CoV-2.
Assuntos
COVID-19 , SARS-CoV-2 , Animais , Cricetinae , Anticorpos Neutralizantes , Anticorpos Antivirais , Antígenos Heterófilos/imunologia , Infecções Irruptivas , COVID-19/prevenção & controle , Mesocricetus , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Imunogenicidade da VacinaRESUMO
White-rot fungi differentially express laccases when they encounter aromatic compounds. However, the underlying mechanisms are still being explored. Here, proteomics analysis revealed that in addition to increased laccase activity, proteins involved in sphingolipid metabolism and toluene degradation as well as some cytochrome P450s (CYP450s) were differentially expressed and significantly enriched during 48 h of o-toluidine exposure, in Trametes hirsuta AH28-2. Two Zn2Cys6-type transcription factors (TFs), TH8421 and TH4300, were upregulated. Bioinformatics docking and isothermal titration calorimetry assays showed that each of them could bind directly to o-toluidine and another aromatic monomer, guaiacol. Binding to aromatic compounds promoted the formation of TH8421/TH4300 heterodimers. TH8421 and TH4300 silencing in T. hirsuta AH28-2 led to decreased transcriptional levels and activities of LacA and LacB upon o-toluidine and guaiacol exposure. EMSA and ChIP-qPCR analysis further showed that TH8421 and TH4300 bound directly with the promoter regions of lacA and lacB containing CGG or CCG motifs. Furthermore, the two TFs were involved in direct and positive regulation of the transcription of some CYP450s. Together, TH8421 and TH4300, two key regulators found in T. hirsuta AH28-2, function as heterodimers to simultaneously trigger the expression of downstream laccases and intracellular enzymes. Monomeric aromatic compounds act as ligands to promote heterodimer formation and enhance the transcriptional activities of the two TFs.IMPORTANCEWhite-rot fungi differentially express laccase isoenzymes when exposed to aromatic compounds. Clarification of the molecular mechanisms underlying differential laccase expression is essential to elucidate how white-rot fungi respond to the environment. Our study shows that two Zn2Cys6-type transcription factors form heterodimers, interact with the promoters of laccase genes, and positively regulate laccase transcription in Trametes hirsuta AH28-2. Aromatic monomer addition induces faster heterodimer formation and rate of activity. These findings not only identify two new transcription factors involved in fungal laccase transcription but also deepen our understanding of the mechanisms underlying the response to aromatics exposure in white-rot fungi.
Assuntos
Proteínas Fúngicas , Regulação Fúngica da Expressão Gênica , Lacase , Trametes , Fatores de Transcrição , Lacase/genética , Lacase/metabolismo , Trametes/enzimologia , Trametes/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Hidrocarbonetos Aromáticos/metabolismoRESUMO
Denitrification is a crucial process in the global nitrogen cycle, in which two functionally equivalent genes, nirS and nirK, catalyse the critical reaction and are usually used as marker genes. The nirK gene can function independently, whereas nirS requires additional genes to encode nitrite reductase and is more sensitive to environmental factors than nirK. However, the ecological differentiation mechanisms of those denitrifying microbial communities and their adaptation strategies to environmental stresses remain unclear. Here, we conducted metagenomic analysis for sediments and bioreactor samples from Lake Donghu, China. We found that nirS-type denitrifying communities had a significantly lower horizontal gene transfer frequency than that of nirK-type denitrifying communities, and nirS gene phylogeny was more congruent with taxonomy than that of nirK gene. Metabolic reconstruction of metagenome-assembled genomes further revealed that nirS-type denitrifying communities have robust metabolic systems for energy conservation, enabling them to survive under environmental stresses. Nevertheless, nirK-type denitrifying communities seemed to adapt to oxygen-limited environments with the ability to utilize various carbon and nitrogen compounds. Thus, this study provides novel insights into the ecological differentiation mechanism of nirS and nirK-type denitrifying communities, as well as the regulation of the global nitrogen cycle and greenhouse gas emissions.
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The external application of nitrogen (N) fertilizers is an important practice for increasing crop production. However, the excessive use of fertilizers significantly increases production costs and causes environmental problems, making the improvement of crop N-use efficiency (NUE) crucial for sustainable agriculture in the future. Here we show that the rice (Oryza sativa) NUE quantitative trait locus DULL NITROGEN RESPONSE1 (qDNR1), which is involved in auxin homeostasis, reflects the differences in nitrate (NO3-) uptake, N assimilation, and yield enhancement between indica and japonica rice varieties. Rice plants carrying the DNR1indica allele exhibit reduced N-responsive transcription and protein abundance of DNR1. This, in turn, promotes auxin biosynthesis, thereby inducing AUXIN RESPONSE FACTOR-mediated activation of NO3- transporter and N-metabolism genes, resulting in improved NUE and grain yield. We also show that a loss-of-function mutation at the DNR1 locus is associated with increased N uptake and assimilation, resulting in improved rice yield under moderate levels of N fertilizer input. Therefore, modulating the DNR1-mediated auxin response represents a promising strategy for achieving environmentally sustainable improvements in rice yield.
Assuntos
Ácidos Indolacéticos/metabolismo , Mutação com Perda de Função/genética , Nitrogênio/metabolismo , Oryza/genética , Oryza/metabolismo , Alelos , Homeostase/genética , Homeostase/fisiologiaRESUMO
Resistance to temozolomide (TMZ), the frontline chemotherapeutic agent for glioblastoma (GBM), has emerged as a formidable obstacle, underscoring the imperative to identify alternative therapeutic strategies to improve patient outcomes. In this study, we comprehensively evaluated a novel agent, O6-methyl-2'-deoxyguanosine-5'-triphosphate (O6-methyl-dGTP) for its anti-GBM activity both in vitro and in vivo. Notably, O6-methyl-dGTP exhibited pronounced cytotoxicity against GBM cells, including those resistant to TMZ and overexpressing O6-methylguanine-DNA methyltransferase (MGMT). Mechanistic investigations revealed that O6-methyl-dGTP could be incorporated into genomic DNA, disrupting nucleotide pools balance, and inducing replication stress, resulting in S-phase arrest and DNA damage. The compound exerted its anti-tumor properties through the activation of AIF-mediated apoptosis and the parthanatos pathway. In vivo studies using U251 and Ln229 cell xenografts supported the robust tumor-inhibitory capacity of O6-methyl-dGTP. In an orthotopic transplantation model with U87MG cells, O6-methyl-dGTP showcased marginally superior tumor-suppressive activity compared to TMZ. In summary, our research, for the first time, underscores the potential of O6-methyl-dGTP as an effective candidate against GBM, laying a robust scientific groundwork for its potential clinical adoption in GBM treatment regimens.
Assuntos
Glioblastoma , Polifosfatos , Humanos , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Antineoplásicos Alquilantes/farmacologia , Antineoplásicos Alquilantes/uso terapêutico , Nucleosídeos/farmacologia , Nucleosídeos/uso terapêutico , Caspases , Linhagem Celular Tumoral , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Nucleotídeos , O(6)-Metilguanina-DNA Metiltransferase/metabolismo , O(6)-Metilguanina-DNA Metiltransferase/farmacologia , O(6)-Metilguanina-DNA Metiltransferase/uso terapêutico , Desoxiguanosina/farmacologia , Desoxiguanosina/uso terapêutico , DNA , Resistencia a Medicamentos AntineoplásicosRESUMO
Kirsten rat sarcoma virus (KRAS) gene mutation is common in colorectal cancer (CRC) and is often predictive of treatment failure and poor prognosis. To understand the mechanism, we compared the transcriptome of CRC patients with wild-type and mutant KRAS and found that KRAS mutation is associated with the overexpression of a secreted serine protease, kallikrein-related peptidase 10 (KLK10). Moreover, using in vitro and in vivo models, we found that KLK10 overexpression favors the rapid growth and liver metastasis of KRAS mutant CRC and can also impair the efficacy of KRAS inhibitors, leading to drug resistance and poor survival. Further functional assays revealed that the oncogenic role of KLK10 is mediated by protease-activated receptor 1 (PAR1). KLK10 cleaves and activates PAR1, which further activates 3-phosphoinositide-dependent kinase 1 (PDK1)-AKT oncogenic pathway. Notably, suppressing PAR1-PDK1-AKT cascade via KLK10 knockdown can effectively inhibit CRC progression and improve the sensitivity to KRAS inhibitor, providing a promising therapeutic strategy. Taken together, our study showed that KLK10 promotes the progression of KRAS mutant CRC via activating PAR1-PDK1-AKT signaling pathway. These findings expanded our knowledge of CRC development, especially in the setting of KRAS mutation, and also provided novel targets for clinical intervention.