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1.
Int J Mol Sci ; 24(2)2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36675157

RESUMO

4-coumarate: CoA ligase (4CL) is not only involved in the biosynthetic processes of flavonoids and lignin in plants but is also closely related to plant tolerance to abiotic stress. UV irradiation can activate the expression of 4CL genes in plants, and the expression of 4CL genes changed significantly in response to different phytohormone treatments. Although the 4CL gene has been cloned in potatoes, there have been fewer related studies of the 4CL gene family on the potato genome-wide scale. In this study, a total of 10 potato 4CL genes were identified in the potato whole genome. Through multiple sequence alignment, phylogenetic analysis as well as gene structure analysis indicated that the potato 4CL gene family could be divided into two subgroups. Combined with promoter cis-acting element analysis, transcriptome data, and RT-qPCR results indicated that potato 4CL gene family was involved in potato response to white light, UV irradiation, ABA treatment, MeJA treatment, and PEG simulated drought stress. Abiotic stresses such as UV, ABA, MeJA, and PEG could promote the up-regulated expression of St4CL6 and St4CL8 but inhibits the expression of St4CL5. The above results will increase our understanding of the evolution and expression regulation of the potato 4CL gene family and provide reference value for further research on the molecular biological mechanism of 4CL participating in response to diverse environmental signals in potatoes.


Assuntos
Solanum tuberosum , Solanum tuberosum/genética , Solanum tuberosum/metabolismo , Ligases/metabolismo , Filogenia , Plantas/metabolismo , Regiões Promotoras Genéticas , Regulação da Expressão Gênica de Plantas , Estresse Fisiológico/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
2.
Arch. bronconeumol. (Ed. impr.) ; 59(1): 10-18, ene. 2023. ilus, graf
Artigo em Inglês | IBECS | ID: ibc-214117

RESUMO

Objective: Explorations have been progressing in decoding the mechanism of non-small cell lung cancer (NSCLC). However, long noncoding RNA small nucleolar RNA host gene 5/microRNA-181c-5p/chromobox protein 4 (SNHG5/miR-181c-5p/CBX4) axis-oriented mechanisms in NSCLC is still in infancy. Therein, this study is proposed to probe this axis in NSCLC progression. Methods: Samples of 86 NSCLC patients were collected and SNHG5, miR-181c-5p and CBX4 expression was detected in NSCLC tissues and cells. NSCLC cells were transfected with plasmids to change SNHG5, miR-181c-5p or CBX4 expression, after which cell functions and phosphorylated (p)-nuclear factor (NF)-κB protein expression were evaluated. The relationships among SNHG5, miR-181c-5p and CBX4 were validated. Tumor xenografts were implemented to verify the roles of SNHG5, miR-181c-5p and CBX4 in tumor growth. Results: Low miR-181c-5p and high SNHG5 and CBX4 levels were found in NSCLC tissues and cells. Restoration of miR-181c-5p or knockdown of SNHG5 or CBX4 restrained NSCLC cell progression and inactivated the NF-κB pathway. Upregulated CBX4 abolished the effects of miR-181c-5p on reducing NSCLC cell progression. SNHG5 regulated the interaction between miR-181c-5p and CBX4. In vivo, restoration of miR-181c-5p or knockdown of SNHG5 or CBX4 retarded the tumor growth. Conclusion: This study has delineated that SNHG5 induces the NF-κB pathway by regulating the miR-181c-5p/CBX4 axis to promote NSCLC progression, which may pave a novel path for NSCLC treatment. (AU)


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , MicroRNAs , Proteínas do Grupo Polycomb , RNA Longo não Codificante , NF-kappa B , Ligases , Linhagem Celular Tumoral
3.
Clin Transl Med ; 13(1): e1007, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36627765

RESUMO

BACKGROUND: SMC5/6 complex plays a vital role in maintaining genome stability, yet the relationship with human diseases has not been described. METHODS: SMC5 variation was identified through whole-exome sequencing (WES) and verified by Sanger sequencing. Immunoprecipitation, cytogenetic analysis, fluorescence activated cell sorting (FACS) and electron microscopy were used to elucidate the cellular consequences of patient's cells. smc5 knockout (KO) zebrafish and Smc5K371del knock-in mouse models were generated by CRISPR-Cas9. RNA-seq, quantitative real-time PCR (qPCR), western blot, microquantitative computed tomography (microCT) and histology were used to explore phenotypic characteristics and potential mechanisms of the animal models. The effects of Smc5 knockdown on mitotic clonal expansion (MCE) during adipogenesis were investigated through Oil Red O staining, proliferation and apoptosis assays in vitro. RESULTS: We identified a homozygous in-frame deletion of Arg372 in SMC5, one of the core subunits of the SMC5/6 complex, from an adult patient with microcephalic primordial dwarfism, chromosomal instability and insulin resistance. SMC5 mutation disrupted its interaction with its interacting protein NSMCE2, leading to defects in DNA repair and chromosomal instability in patient fibroblasts. Smc5 KO zebrafish showed microcephaly, short length and disturbed glucose metabolism. Smc5 depletion triggers a p53-related apoptosis, as concomitant deletion of the p53 rescued growth defects phenotype in zebrafish. An smc5K371del knock-in mouse model exhibited high mortality, severe growth restriction and fat loss. In 3T3-L1 cells, the knockdown of smc5 results in impaired MCE, a crucial step in adipogenesis. This finding implies that defective cell survival and differentiation is an important mechanism linking growth disorders and metabolic homeostasis imbalance.


Assuntos
Nanismo , Resistência à Insulina , Animais , Camundongos , Adulto , Humanos , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Resistência à Insulina/genética , Proteína Supressora de Tumor p53/genética , Nanismo/genética , Fenótipo , Instabilidade Cromossômica , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Ligases/genética , Ligases/metabolismo
4.
Int J Mol Sci ; 24(2)2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36674458

RESUMO

Trehalose is a nonreducing disaccharide that is widely distributed in various organisms. Trehalose-6-phosphate synthase (TPS) is a critical enzyme responsible for the biosynthesis of trehalose, which serves important functions in growth and development, defense, and stress resistance. Although previous studies have found that the clubroot pathogen Plasmodiophora brassicae can lead to the accumulation of trehalose in infected Arabidopsis organs, it has been proposed that much of the accumulated trehalose is derived from the pathogen. At present, there is very little evidence to verify this view. In this study, a comprehensive analysis of the TPS gene family was conducted in Brassica rapa and Plasmodiophora brassicae. A total of 14 Brassica rapa TPS genes (BrTPSs) and 3 P. brassicae TPS genes (PbTPSs) were identified, and the evolutionary characteristics, functional classification, and expression patterns were analyzed. Fourteen BrTPS genes were classified into two distinct classes according to phylogeny and gene structure. Three PbTPSs showed no significant differences in gene structure and protein conserved motifs. However, evolutionary analysis showed that the PbTPS2 gene failed to cluster with PbTPS1 and PbTPS3. Furthermore, cis-acting elements related to growth and development, defense and stress responsiveness, and hormone responsiveness were predicted in the promoter region of the BrTPS genes. Expression analysis of most BrTPS genes at five stages after P. brassicae interaction found no significant induction. Instead, the expression of the PbTPS genes of P. brassicae was upregulated, which was consistent with the period of trehalose accumulation. This study deepens our understanding of the function and evolution of BrTPSs and PbTPSs. Simultaneously, clarifying the biosynthesis of trehalose in the interaction between Brassica rapa and P. brassicae is also of great significance.


Assuntos
Arabidopsis , Brassica rapa , Brassica , Plasmodioforídeos , Brassica rapa/genética , Trealose/genética , Plasmodioforídeos/genética , Ligases , Brassica/genética , Doenças das Plantas/genética
5.
Biochemistry ; 62(2): 462-475, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36577516

RESUMO

Ribosomally synthesized and post-translationally modified peptides (RiPPs) are natural products with remarkable chemical and functional diversities. These peptides are often synthesized as signals or antibiotics and frequently associated with quorum sensing (QS) systems. With the increasing number of available genomes, many hitherto unseen RiPP biosynthetic pathways have been mined, providing new resources for novel bioactive compounds. Herein, we investigated the underexplored biosynthetic potential of Streptococci, prevalent bacteria in mammal-microbiomes that include pathogenic, mutualistic, and commensal members. Using the transcription factor-centric genome mining strategy, we discovered a new family of lanthipeptide biosynthetic loci under the control of potential QS. By in vitro studies, we investigated the reaction of one of these lanthipeptide synthetases and found that it installs only one lanthionine moiety onto its short precursor peptide by connecting a conserved TxxC region. Bioinformatics and in vitro studies revealed that these lanthipeptide synthetases (class VI) are novel lanthipeptide synthetases with a truncated lyase, a kinase, and a truncated cyclase domain. Our data provide important insights into the processing and evolution of lanthipeptide synthetase to tailor smaller substrates. The data are important for obtaining a mechanistic understanding of the post-translational biosynthesis machinery of the growing variety of lanthipeptides.


Assuntos
Produtos Biológicos , Ligases , Ligases/metabolismo , Produtos Biológicos/metabolismo , Peptídeos/química , Antibacterianos/metabolismo , Ribossomos/metabolismo , Processamento de Proteína Pós-Traducional
6.
Biol Chem ; 404(1): 29-39, 2023 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-36215729

RESUMO

Hepatocellular carcinoma (HCC) is the most common primary human liver malignancy with high mortality. Liver cancer stem cells (CSCs) have been demonstrated to contribute to the recurrence, metastasis and drug resistance of liver cancer. Human HCC cohort analysis indicated that the epigenetic regulator polycomb chromobox homologue 4 (CBX4) was overexpressed in human HCC. Moreover, we found that CBX4 expression was significantly higher in CD44+ CD133+ Hep3B CSCs. Functionally, we demonstrated that CBX4 regulated cell proliferation, self-renewal, and metastasis ability of Hep3B CSCs. Bioinformatics analysis predicted that CBX4 was a direct target of microRNA-6838-5p (miR-6838-5p), which was further confirmed by luciferase reporter assay. MiR-6838-6p was down-regulated in HCC tumors and overexpression of miR-6838-5p attenuated the malignant traits of human liver CSCs in vitro. In addition, we found that miR-6838-5p/CBX4 axis modulates the biological properties of human liver CSCs via regulating ERK signaling. Overexpression of miR-6838-5p suppressed Hep3B xenograft tumor growth in vivo, while CBX4 overexpression abrogated the suppression effect, restored the angiogenesis, epithelial-to-mesenchymal transition (EMT), and ERK signaling in Hep3B tumor. In summary, our findings suggest that miR-6838-5p/CBX4 axis regulates liver tumor development and metastasis, which could be utilized as potential therapeutic target for HCC treatment.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral , Células-Tronco Neoplásicas/patologia , Proliferação de Células , Ligases/metabolismo , Proteínas do Grupo Polycomb/metabolismo
7.
Nat Chem Biol ; 19(1): 55-63, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36577875

RESUMO

Engineered destruction of target proteins by recruitment to the cell's degradation machinery has emerged as a promising strategy in drug discovery. The majority of molecules that facilitate targeted degradation do so via a select number of ubiquitin ligases, restricting this therapeutic approach to tissue types that express the requisite ligase. Here, we describe a new strategy of targeted protein degradation through direct substrate recruitment to the 26S proteasome. The proteolytic complex is essential and abundantly expressed in all cells; however, proteasomal ligands remain scarce. We identify potent peptidic macrocycles that bind directly to the 26S proteasome subunit PSMD2, with a 2.5-Å-resolution cryo-electron microscopy complex structure revealing a binding site near the 26S pore. Conjugation of this macrocycle to a potent BRD4 ligand enabled generation of chimeric molecules that effectively degrade BRD4 in cells, thus demonstrating that degradation via direct proteasomal recruitment is a viable strategy for targeted protein degradation.


Assuntos
Proteínas Nucleares , Fatores de Transcrição , Proteínas Nucleares/metabolismo , Microscopia Crioeletrônica , Fatores de Transcrição/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Ligases/metabolismo , Ubiquitina-Proteína Ligases/metabolismo
8.
Biotechnol Lett ; 45(2): 273-286, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36586051

RESUMO

OBJECTIVE: To increase the production of (R)-α-lipoic acid directly from octanoic acid using engineered Escherichia coli with the regeneration of S-adenosylmethionine. RESULTS: The biosynthesis of (R)-α-lipoic acid (LA) in E. coli BL21(DE3) is improved by co-expression of lipoate-protein ligase A (LplA) from E. coli MG1655 and lipoate synthase (LipA) from Vibrio vulnificus. The engineered strain produces 20.99 µg l-1 of LA in shake flask cultures. The titers of LA are increased to 169.28 µg l-1 after the optimization of the medium components and fermentation conditions. We find that the [4Fe-4S] cluster is important for the activity of LipA and co-expression of iscSUA promotes the regeneration of the [4Fe-4S] cluster and leads to the highest LA titer of 589.30 µg l-1. CONCLUSION: The method described here can be widely applied for the biosynthesis of (R)-α-lipoic acid and other metabolites.


Assuntos
Escherichia coli , Ácido Tióctico , Escherichia coli/genética , Escherichia coli/metabolismo , Ácido Tióctico/metabolismo , Proteínas de Bactérias/genética , Engenharia Metabólica , Ligases
9.
Biochem Biophys Res Commun ; 643: 61-68, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36586160

RESUMO

Nicotinamide adenine dinucleotide (NAD) is an essential coenzyme in the kidney. The first step in de novo NAD synthesis is regulated by indoleamine 2,3-dioxygenase (IDO), a tryptophan-catabolizing enzyme. Here, we investigated NAD synthetic flux and NAD levels in podocytes under diabetic conditions. We also studied the effects of IDO overexpression on NAD synthetic flux and high glucose (HG)-induced podocyte injury. NAD synthetases in the de novo, Preiss-Handler and salvage pathways were analyzed using in vivo single-nucleus RNA sequencing datasets (GSE131882) of control and diabetic kidney disease (DKD). The mRNA levels of these NAD synthetases were measured in vitro in HG-treated podocytes. The effects of IDO on NAD synthesis were examined by transducing cultured podocytes with an adenovirus encoding IDO, and apoptosis, podocyte markers and mobility were investigated. Cellular transcriptome analysis revealed that control podocytes had relatively low levels of NAD synthetases. In DKD podocytes, de novo NAD synthetase levels were further downregulated. IDO levels were virtually undetectable and did not increase in DKD. In vitro experiments confirmed aberrant de novo NAD synthetic flux and decreased IDO levels in HG-treated podocytes. Overexpression of IDO promoted NAD de novo synthesis, reduced NAD-bypass metabolic enzyme, increased NAD content and recovered podocyte injury markers under diabetic conditions. Taken together, our findings suggest that the de novo NAD synthetic flux is aberrant in DKD, and IDO promotes de novo NAD synthesis and NAD levels, as well as alleviates injury in HG-treated podocytes.


Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , Podócitos , Humanos , NAD/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Podócitos/metabolismo , Ligases
10.
Eur J Pharmacol ; 940: 175457, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36529278

RESUMO

Accumulating evidence suggests that de novo lipogenesis is a typical characteristic facilitating nonalcoholic fatty liver disease (NAFLD) progression. Gallic acid (GA) is a naturally occurring phenolic acid with metabolic disease-related clinical significance and preclinical benefits. This study aimed to evaluate the anti-steatotic potentials of GA in a fructose-induced NAFLD mouse model featuring a hepatic lipogenic phenotype. The results revealed that GA alleviated hepatic steatosis, oxidative stress, and inflammatory response in fructose-fed mice. Mechanistically, GA treatment restored AMP-activated protein kinase α (AMPKα) phosphorylation, resulting in downregulations of pro-lipogenic factors, including sterol regulatory element binding protein-1 (SREBP-1), fatty acid synthetase (FASN), and acetyl-CoA carboxylase (ACC), in hepatocytes of mice and in vitro. Furthermore, computational docking analysis indicated that GA could directly interact with AMPKα/ß subunits to stabilize its activation. These results suggest that GA ameliorates fructose-induced hepatosteatosis by restraining hepatic lipogenesis via AMPK-dependent suppression of the SREBP-1/ACC/FASN cascade. Altogether, this study demonstrates that GA supplement may be a promising therapeutic strategy in NAFLD, especially in the subset with enhanced hepatic lipogenesis.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Lipogênese/genética , Acetil-CoA Carboxilase/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Ácidos Graxos/metabolismo , Ligases/metabolismo , Ácido Gálico/farmacologia , Ácido Gálico/uso terapêutico , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Frutose/efeitos adversos , Fígado/metabolismo , Ácido Graxo Sintase Tipo I/metabolismo
11.
Acta Biochim Biophys Sin (Shanghai) ; 54(11): 1-10, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36471952

RESUMO

Gefitinib, an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI),is the currently recommended first-line therapy for advanced EGFR-mutant lung cancer, and understanding the mechanism of resistance is the key to formulating therapeutic strategies for EGFR-TKIs. In this study, we evaluate the expression patterns and potential biological functions of the pseudogene DUXAP10 in gefitinib resistance. We find that pseudogene DUXAP10 expression is significantly upregulated in NSCLC gefitinib-resistant cells and tissues. Gain and loss of function assays reveal that knockdown of DUXAP10 by siRNA reverses gefitinib resistance both in vitro and in vivo. Furthermore, DUXAP10 interacts with the histone methyltransferase enhancer of zeste homolog 2 (EZH2) to repress the expression of 2',5'-oligoadenylate synthetase (OAS2). Overall, our study highlights the pivotal role of DUXAP10 in gefitinib resistance, and the DUXAP10/EZH2/OAS2 axis might be a promising therapeutic target to overcome acquired gefitinib resistance in NSCLC.


Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Gefitinibe/farmacologia , Gefitinibe/uso terapêutico , Pseudogenes/genética , Ligases/genética , Ligases/farmacologia , Ligases/uso terapêutico , Receptores ErbB/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Linhagem Celular Tumoral , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico
12.
Proc Natl Acad Sci U S A ; 119(49): e2209256119, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36454752

RESUMO

Auxin inactivation is critical for plant growth and development. To develop plant growth regulators functioning in auxin inactivation pathway, we performed a phenotype-based chemical screen in Arabidopsis and identified a chemical, nalacin, that partially mimicked the effects of auxin. Genetic, pharmacological, and biochemical approaches demonstrated that nalacin exerts its auxin-like activities by inhibiting indole-3-acetic acid (IAA) conjugation that is mediated by Gretchen Hagen 3 (GH3) acyl acid amido synthetases. The crystal structure of Arabidopsis GH3.6 in complex with D4 (a derivative of nalacin) together with docking simulation analysis revealed the molecular basis of the inhibition of group II GH3 by nalacin. Sequence alignment analysis indicated broad bioactivities of nalacin and D4 as inhibitors of GH3s in vascular plants, which were confirmed, at least, in tomato and rice. In summary, our work identifies nalacin as a potent inhibitor of IAA conjugation mediated by group II GH3 that plays versatile roles in hormone-regulated plant development and has potential applications in both basic research and agriculture.


Assuntos
Arabidopsis , Ligases , Arabidopsis/genética , Ácidos Indolacéticos/farmacologia , Fenômenos Químicos , Reguladores de Crescimento de Plantas/farmacologia , Testes Genéticos
13.
Nat Commun ; 13(1): 7833, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36539424

RESUMO

During lagging strand synthesis, DNA Ligase 1 (Lig1) cooperates with the sliding clamp PCNA to seal the nicks between Okazaki fragments generated by Pol δ and Flap endonuclease 1 (FEN1). We present several cryo-EM structures combined with functional assays, showing that human Lig1 recruits PCNA to nicked DNA using two PCNA-interacting motifs (PIPs) located at its disordered N-terminus (PIPN-term) and DNA binding domain (PIPDBD). Once Lig1 and PCNA assemble as two-stack rings encircling DNA, PIPN-term is released from PCNA and only PIPDBD is required for ligation to facilitate the substrate handoff from FEN1. Consistently, we observed that PCNA forms a defined complex with FEN1 and nicked DNA, and it recruits Lig1 to an unoccupied monomer creating a toolbelt that drives the transfer of DNA to Lig1. Collectively, our results provide a structural model on how PCNA regulates FEN1 and Lig1 during Okazaki fragments maturation.


Assuntos
DNA Polimerase III , Replicação do DNA , Humanos , Antígeno Nuclear de Célula em Proliferação/metabolismo , DNA Polimerase III/metabolismo , Ligases/metabolismo , DNA/metabolismo , Endonucleases Flap/metabolismo , DNA Ligase Dependente de ATP/genética , DNA Ligase Dependente de ATP/metabolismo
14.
Int J Mol Sci ; 23(23)2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36499418

RESUMO

Mycothiol (MSH), the major cellular thiol in Mycobacterium tuberculosis (Mtb), plays an essential role in the resistance of Mtb to various antibiotics and oxidative stresses. MshC catalyzes the ATP-dependent ligation of 1-O-(2-amino-2-deoxy-α-d-glucopyranosyl)-d-myo-inositol (GlcN-Ins) with l-cysteine (l-Cys) to form l-Cys-GlcN-Ins, the penultimate step in MSH biosynthesis. The inhibition of MshC is lethal to Mtb. In the present study, five new cysteinyl-sulfonamides were synthesized, and their binding affinity with MshC was evaluated using a thermal shift assay. Two of them bind the target with EC50 values of 219 and 231 µM. Crystal structures of full-length MshC in complex with these two compounds showed that they were bound in the catalytic site of MshC, inducing dramatic conformational changes of the catalytic site compared to the apo form. In particular, the observed closure of the KMSKS loop was not detected in the published cysteinyl-sulfamoyl adenosine-bound structure, the latter likely due to trypsin treatment. Despite the confirmed binding to MshC, the compounds did not suppress Mtb culture growth, which might be explained by the lack of adequate cellular uptake. Taken together, these novel cysteinyl-sulfonamide MshC inhibitors and newly reported full-length apo and ligand-bound MshC structures provide a promising starting point for the further development of novel anti-tubercular drugs targeting MshC.


Assuntos
Ligases , Mycobacterium tuberculosis , Proteínas de Bactérias/metabolismo , Cisteína/metabolismo , Glicopeptídeos/química , Inositol/metabolismo , Ligases/metabolismo , Mycobacterium smegmatis/metabolismo , Mycobacterium tuberculosis/metabolismo , Sulfonamidas/farmacologia
15.
Int J Mol Sci ; 23(23)2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36499241

RESUMO

IFN-I is the key regulatory component activating and modulating the response of innate and adaptive immune system to bacterial as well as viral pathogens. IFN-I promotes the expression of IFN-induced genes (ISG) and, consequently, the production of chemokines, e.g., CXCL10. Those chemokines control migration and localization of immune cells in tissues, and, thus, are critical to the function of the innate immune system during infection. Consequently, the regulation of IFN-I signaling is essential for the proper induction of an immune response. Our previous study has shown that E3 ubiquitin ligase Pellino3 positively regulates IFNß expression and secretion. Herein, we examined the role of Pellino3 ligase in regulating CXCL10 expression in response to IFNß stimulation. Our experiments were carried out on murine macrophage cell line (BMDM) and human monocytes cell line (THP-1) using IFNß as a IFNAR ligand. We demonstrate that Pellino3 is important for IFNß-induced phosphorylation and nuclear translocation of STAT1/STAT2/IRF9 complex which interacts with CXCL10 promoter and enhances its expression. In this study, we characterize a novel molecular mechanism allowing Pellino3-dependent modulation of the IFNß-induced response in BMDM and THP-1 cell lines.


Assuntos
Quimiocina CXCL10 , Interferon Tipo I , Animais , Humanos , Camundongos , Quimiocina CXCL10/genética , Quimiocina CXCL10/metabolismo , Interferon Tipo I/metabolismo , Ligases/metabolismo , Macrófagos/metabolismo , Monócitos/metabolismo , Transdução de Sinais , Interferon beta/farmacologia
16.
World J Microbiol Biotechnol ; 38(12): 255, 2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36319705

RESUMO

Phosphate (Pi) is essential for life as it is an integral part of the universal chemical energy adenosine triphosphate (ATP), and macromolecules such as, DNA, RNA proteins and lipids. Despite the core roles and the need of this nutrient in living cells, some bacteria can grow in environments that are poor in Pi. The metabolic mechanisms that enable bacteria to proliferate in a low phosphate environment are not fully understood. In this study, the soil microbe Pseudomonas (P.) fluorescens was cultured in a control and a low Pi (stress) medium in order to delineate how energy homeostasis is maintained. Although there was no significant variation in biomass yield in these cultures, metabolites like isocitrate, oxaloacetate, pyruvate and phosphoenolpyruvate (PEP) were markedly increased in the phosphate-starved condition. Components of the glycolytic, glyoxylate and tricarboxylic acid cycles operated in tandem to generate ATP by substrate level phosphorylation (SLP) as NADH-producing enzymes were impeded. The α-ketoglutarate (KG) produced when glutamine, the sole carbon nutrient was transformed into phosphoenol pyruvate (PEP) and succinyl-CoA (SC), two high energy moieties. The metabolic reprogramming orchestrated by isocitrate lyase (ICL), phosphoenolpyruvate synthase (PEPS), pyruvate phosphate dikinase (PPDK), and succinyl-CoA synthetase fulfilled the ATP budget. Cell free extract experiments confirmed ATP synthesis in the presence of such substrates as PEP, oxaloacetate and isocitrate respectively. Gene expression profiling revealed elevated transcripts associated with numerous enzymes including ICL, PEPS, and succinyl-CoA synthetase (SCS). This microbial adaptation will be critical in promoting biological activity in Pi-poor ecosystems.


Assuntos
Pseudomonas fluorescens , Pseudomonas fluorescens/metabolismo , Trifosfato de Adenosina/metabolismo , Isocitratos/metabolismo , Fosfatos/metabolismo , Ecossistema , Fosfoenolpiruvato/metabolismo , Homeostase , Ácido Pirúvico/metabolismo , Oxaloacetatos/metabolismo , Ligases/metabolismo
17.
Nat Microbiol ; 7(12): 2101-2113, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36376394

RESUMO

After viral entry and reverse transcription, HIV-1 proviruses that fail to integrate are epigenetically silenced, but the underlying mechanism has remained unclear. Using a genome-wide CRISPR/Cas9 knockout screen, we identified the host SMC5/6 complex as essential for this epigenetic silencing. We show that SMC5/6 binds to and then SUMOylates unintegrated chromatinized HIV-1 DNA. Inhibition of SUMOylation, either by point mutagenesis of the SMC5/6 component NSMCE2-a SUMO E3 ligase-or using the SUMOylation inhibitor TAK-981, prevents epigenetic silencing, enables transcription from unintegrated HIV-1 DNA and rescues the replication of integrase-deficient HIV-1. Finally, we show that blocking SMC5/6 complex expression, or inhibiting its SUMOylation activity, suppresses the establishment of latent HIV-1 infections in both CD4+ T cell lines and primary human T cells. Collectively, our data show that the SMC5/6 complex plays a direct role in mediating the establishment of HIV-1 latency by epigenetically silencing integration-competent HIV-1 proviruses before integration.


Assuntos
Infecções por HIV , HIV-1 , Humanos , HIV-1/fisiologia , Infecções por HIV/genética , Latência Viral/genética , Provírus/genética , Provírus/metabolismo , DNA , Epigênese Genética , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Ligases/genética
18.
Nat Commun ; 13(1): 6647, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36333342

RESUMO

Endothelial nitric oxide synthase (eNOS) decreases following inflammatory stimulation. As a master regulator of endothelial homeostasis, maintaining optimal eNOS levels is important during cardiovascular events. However, little is known regarding the mechanism of eNOS protection. In this study, we demonstrate a regulatory role for endothelial expression of 2'-5' oligoadenylate synthetase-like 1 (OASL1) in maintaining eNOS mRNA stability during athero-prone conditions and consider its clinical implications. A lack of endothelial Oasl1 accelerated plaque progression, which was preceded by endothelial dysfunction, elevated vascular inflammation, and decreased NO bioavailability following impaired eNOS expression. Mechanistically, knockdown of PI3K/Akt signaling-dependent OASL expression increased Erk1/2 and NF-κB activation and decreased NOS3 (gene name for eNOS) mRNA expression through upregulation of the negative regulatory, miR-584, whereas a miR-584 inhibitor rescued the effects of OASL knockdown. These results suggest that OASL1/OASL regulates endothelial biology by protecting NOS3 mRNA and targeting miR-584 represents a rational therapeutic strategy for eNOS maintenance in vascular disease.


Assuntos
Aterosclerose , MicroRNAs , Humanos , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Ligases/metabolismo , Células Endoteliais/metabolismo , MicroRNAs/genética , Aterosclerose/genética , Aterosclerose/prevenção & controle , Aterosclerose/metabolismo , RNA Mensageiro/metabolismo , Estabilidade de RNA , Óxido Nítrico/metabolismo , Células Cultivadas
19.
Int J Mol Sci ; 23(21)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36361884

RESUMO

Under stress conditions, transfer RNAs (tRNAs) are cleaved by stress-responsive RNases such as angiogenin, generating tRNA-derived RNAs called tiRNAs. As tiRNAs contribute to cytoprotection through inhibition of translation and prevention of apoptosis, the regulation of tiRNA production is critical for cellular stress response. Here, we show that RTCB ligase complex (RTCB-LC), an RNA ligase complex involved in endoplasmic reticulum (ER) stress response and precursor tRNA splicing, negatively regulates stress-induced tiRNA production. Knockdown of RTCB significantly increased stress-induced tiRNA production, suggesting that RTCB-LC negatively regulates tiRNA production. Gel-purified tiRNAs were repaired to full-length tRNAs by RtcB in vitro, suggesting that RTCB-LC can generate full length tRNAs from tiRNAs. As RTCB-LC is inhibited under oxidative stress, we further investigated whether tiRNA production is promoted through the inhibition of RTCB-LC under oxidative stress. Although hydrogen peroxide (H2O2) itself did not induce tiRNA production, it rapidly boosted tiRNA production under the condition where stress-responsive RNases are activated. We propose a model of stress-induced tiRNA production consisting of two factors, a trigger and booster. This RTCB-LC-mediated boosting mechanism may contribute to the effective stress response in the cell.


Assuntos
Peróxido de Hidrogênio , RNA de Transferência , Peróxido de Hidrogênio/farmacologia , RNA de Transferência/metabolismo , Estresse Oxidativo , Splicing de RNA , Ligases/genética
20.
Int J Mol Sci ; 23(21)2022 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-36361943

RESUMO

Size is the most important quality attribute of giant pumpkin fruit. Different concentrations and application frequencies of α-naphthaleneacetic acid (NAA) and 24-epibrassinolide (EBR) were sprayed on the leaves and fruits of giant pumpkin at different growth stages to determine their effects and the mechanism responsible for fruit size increase. NAA+EBR application improved source strength, and further analysis indicated that NAA+EBR markedly boosted net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) and the expression level and activity of galactitol synthetase (GolS), raffinose synthetase (RS), and stachyose synthetase (STS), resulting in an increase in the synthesis of photoassimilate, especially stachyose. Concomitantly, NAA+EBR spray increased stachyose and sucrose contents throughout pumpkin fruit growth and the concentrations of glucose and fructose at 0 and 20 days post-anthesis (DPA) in peduncle phloem sap, implying that such treatment improved the efficiency of assimilate transport from the peduncle to the fruit. Furthermore, it improved the expression and activity of alkaline α-galactosidase (AGA), facilitating assimilate unloading, providing carbon skeletons and energy for fruit growth, and increasing fruit weight by more than 44.1%. Therefore, exogenous NAA and EBR increased source capacity, transportation efficiency, and sink strength, overall promoting the synthesis and distribution of photoassimilate, ultimately increasing fruit size.


Assuntos
Cucurbita , Frutas , Frutas/metabolismo , Açúcares/metabolismo , Ligases/metabolismo
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