Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
Mais filtros








Intervalo de ano de publicação
1.
Int J Mol Sci ; 24(4)2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36834556

RESUMO

Plant transcriptome contains an enormous amount of non-coding RNAs (ncRNAs) that do not code for proteins but take part in regulating gene expression. Since their discovery in the early 1990s, much research has been conducted to elucidate their function in the gene regulatory network and their involvement in plants' response to biotic/abiotic stresses. Typically, 20-30 nucleotide-long small ncRNAs are a potential target for plant molecular breeders because of their agricultural importance. This review summarizes the current understanding of three major classes of small ncRNAs: short-interfering RNAs (siRNAs), microRNA (miRNA), and transacting siRNAs (tasiRNAs). Furthermore, their biogenesis, mode of action, and how they have been utilized to improve crop productivity and disease resistance are discussed here.


Assuntos
MicroRNAs , RNA Longo não Codificante , Pequeno RNA não Traduzido , Regulação da Expressão Gênica de Plantas , RNA Interferente Pequeno/genética , MicroRNAs/genética , Plantas/metabolismo , RNA de Plantas/genética
2.
Int J Mol Sci ; 23(23)2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36498906

RESUMO

Brassinosteroid hormones (BRs) multitask to smoothly regulate a broad spectrum of vital physiological processes in plants, such as cell division, cell expansion, differentiation, seed germination, xylem differentiation, reproductive development and light responses (photomorphogenesis and skotomorphogenesis). Their importance is inferred when visible abnormalities arise in plant phenotypes due to suboptimal or supraoptimal hormone levels. This group of steroidal hormones are major growth regulators, having pleiotropic effects and conferring abiotic stress resistance to plants. Numerous abiotic stresses are the cause of significant loss in agricultural yield globally. However, plants are well equipped with efficient stress combat machinery. Scavenging reactive oxygen species (ROS) is a unique mechanism to combat the deleterious effects of abiotic stresses. In light of numerous reports in the past two decades, the complex BR signaling under different stress conditions (drought, salinity, extreme temperatures and heavy metals/metalloids) that drastically hinders the normal metabolism of plants is gradually being untangled and revealed. Thus, crop improvement has substantial potential by tailoring either the brassinosteroid signaling, biosynthesis pathway or perception. This review aims to explore and dissect the actual mission of BRs in signaling cascades and summarize their positive role with respect to abiotic stress tolerance.


Assuntos
Brassinosteroides , Estresse Fisiológico , Brassinosteroides/metabolismo , Estresse Fisiológico/genética , Plantas/metabolismo , Secas , Hormônios/metabolismo , Reguladores de Crescimento de Plantas/metabolismo
3.
Artigo em Inglês | MEDLINE | ID: mdl-36141455

RESUMO

Endothelin 1 (EDN1) encodes a potent endogenous vasoconstrictor, ET1, to maintain vascular homeostasis and redistribution of tissue blood flow during exercise. One of the EDN1 missense polymorphisms, rs5370 G/T, has strongly been associated with cardiopulmonary diseases. This study investigated the impact of rs5370 polymorphism in high-altitude pulmonary oedema (HAPE) disorder or maladaptation and adaptation physiology in a well-characterized case-control study of high-altitude and low-altitude populations comprising 310 samples each of HAPE-patients, HAPE-free controls and native highlanders. The rs5370 polymorphism was genotyped, and the gene expression and plasma level of EDN1 were evaluated. The functional relevance of each allele was investigated in the human embryonic kidney 293 cell line after exposure to hypoxia and computationally. The T allele was significantly more prevalent in HAPE-p compared to HAPE-f and HLs. The EDN1 gene expression and ET1 bio-level were significantly elevated in HAPE-p compared to controls. Compared to the G allele, the T allele was significantly associated with elevated levels of ET-1 in all three study groups and cells exposed to hypoxia. The in silico studies further confirmed the stabilizing effect of the T allele on the structural integrity and function of ET1 protein. The ET1 rs5370 T allele is associated with an increased concentration of ET-1 in vivo and in vitro, establishing it as a potent marker in the adaptation/maladaptation physiology under the high-altitude environment. This could also be pertinent in endurance exercises at high altitudes.


Assuntos
Doença da Altitude , Endotelina-1 , Altitude , Doença da Altitude/genética , Estudos de Casos e Controles , Endotelina-1/genética , Humanos , Hipóxia/metabolismo , Vasoconstritores
4.
Plants (Basel) ; 11(11)2022 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-35684223

RESUMO

Plants' stress response machinery is characterized by an intricate network of signaling cascades that receive and transmit environmental cues and ultimately trigger transcriptional reprogramming. The family of epigenetic regulators that are the key players in the stress-induced signaling cascade comprise of chromatin remodelers, histone modifiers, DNA modifiers and regulatory non-coding RNAs. Changes in the histone modification and DNA methylation lead to major alterations in the expression level and pattern of stress-responsive genes to adjust with abiotic stress conditions namely heat, cold, drought and salinity. The spotlight of this review falls primarily on the chromatin restructuring under severe abiotic stresses, crosstalk between epigenetic regulators along with a brief discussion on stress priming in plants.

5.
Front Plant Sci ; 13: 885128, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35645997

RESUMO

RNA interference (RNAi) has been exploited by scientists worldwide to make a significant contribution in the arena of sustainable agriculture and integrated pest management. These strategies are of an imperative need to guarantee food security for the teeming millions globally. The already established deleterious effects of chemical pesticides on human and livestock health have led researchers to exploit RNAi as a potential agri-biotechnology tool to solve the burning issue of agricultural wastage caused by pests and pathogens. On the other hand, CRISPR/Cas9, the latest genome-editing tool, also has a notable potential in this domain of biotic stress resistance, and a constant endeavor by various laboratories is in progress for making pathogen-resistant plants using this technique. Considerable outcry regarding the ill effects of genetically modified (GM) crops on the environment paved the way for the research of RNAi-induced double-stranded RNAs (dsRNA) and their application to biotic stresses. Here, we mainly focus on the application of RNAi technology to improve disease resistance in plants and its relevance in today's CRISPR-dominated world in terms of exogenous application of dsRNAs. We also focused on the ongoing research, public awareness, and subsequent commercialization of dsRNA-based biocontrol products.

6.
Curr Genet ; 68(1): 15-25, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34480234

RESUMO

No effective vaccine is available for any parasitic disease. The treatment to those is solely dependent on chemotherapy, which is always threatened due to development of drug resistance in bugs. This warrants identification of new drug targets. Here, we discuss Nucleoside diphosphate kinases (NDKs) of pathogens that alter host's intra and extracellular environment, as novel drug targets to simultaneously tackle multiple pathogens. NDKs having diverse functions, are highly conserved among prokaryotes and eukaryotes (the mammal NDKs are called NMEs [non-metastatic enzymes]). However, NDKs and NMEs have been separately analysed in the past for their structure and functions. The role of NDKs of pathogen in modulation of inflammation, phagocytosis, apoptosis, and ROS generation in host is known. Conversely, its combined contribution in host-pathogen interaction has not been studied yet. Through the sequence and domain analysis, we found that NDKs can be classified in two groups. One group comprised NMEs 1-4 and few NDKs of select essential protozoan parasites and the bacterium Mycobacterium tuberculosis. The other group included NME7 and the other NDKs of those parasites, posing challenges in the development of drugs specifically targeting pathogen NDKs, without affecting NME7. However, common drugs targeting group 2 NDKs of pathogens can be designed, as NME7 of group 2 is expressed only in ciliated host cells. This review thus analyses comparatively for the first time the structures and functions of human NMEs and pathogen NDKs and predicts the possibilities of NDKs as drug targets. In addition, pathogen NDKs have been now provided a nomenclature in alignment with the NMEs of humans.


Assuntos
Mycobacterium tuberculosis , Núcleosídeo-Difosfato Quinase , Animais , Apoptose , Interações Hospedeiro-Patógeno/genética , Humanos , Mycobacterium tuberculosis/genética , Núcleosídeo-Difosfato Quinase/genética
7.
Sci Rep ; 11(1): 4129, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33602957

RESUMO

Piriformospora indica, a root endophytic fungus, augments plant nutrition and productivity as well as protects plants against pathogens and abiotic stresses. High salinity is a major problem faced by plants as well as by microbes. Until now, the precise mechanism of salt stress tolerance in P. indica has remained elusive. In this study, the transcriptomes of control and salt-treated (0.5 M NaCl) P. indica were sequenced via the RNA-seq approach. A total of 30,567 transcripts and 15,410 unigenes for P. indica were obtained from 7.3 Gb clean reads. Overall 661 differentially expressed genes (DEGs) between control and treated samples were retrieved. Gene ontology (GO) and EuKaryotic Orthologous Groups (KOG) enrichments revealed that DEGs were specifically involved in metabolic and molecular processes, such as "response to salt stress", "oxidoreductase activity", "ADP binding", "translation, ribosomal structure and biogenesis", "cytoskeleton", and others. The unigenes involved in "cell wall integrity", "sterol biosynthesis", and "oxidative stress" such as Rho-type GTPase, hydroxymethylglutaryl-CoA synthase, and thioredoxin peroxidase were up-regulated in P. indica subjected to salt stress. The salt-responsive DEGs have shown that they might have a potential role in salt stress regulation. Our study on the salt-responsive DEGs established a foundation for the elucidation of molecular mechanisms related to P. indica stress adaptation and a future reference for comparative functional genomics studies of biotechnologically important fungal species.


Assuntos
Basidiomycota/genética , Estresse Salino/genética , Transcrição Gênica/genética , Perfilação da Expressão Gênica/métodos , RNA-Seq/métodos , Salinidade , Tolerância ao Sal/genética , Estresse Fisiológico/genética , Transcriptoma/genética
8.
Anticancer Agents Med Chem ; 21(13): 1697-1707, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33231161

RESUMO

BACKGROUND: Chlorophytum comosum, popularly known as Spider Ivy, is used as a medicinal plant in traditional Chinese medicine, however, its detailed chemical composition and biological activity are yet unexplored. OBJECTIVE: To carry out the phytochemical investigation on different parts of Chlorophytum comosum using GCMS/ LC-ESI-MS and evaluation of its antioxidant, hemolytic and antiproliferative potential on breast cancer (MCF-7), lung cancer (A549, H1299) and normal lung (L-132) cell lines. METHODS: Chemical constituents from aqueous roots and leaves extracts were identified using LC-ESI-MS/GCMS. The identified compounds were annotated based on the match of mass spectra with the literature using NIST 14 and METLIN databases. Antioxidant activity was studied using DPPH, FRAP and TPC assays. The antiproliferative effects of ethanolic roots and leaves extracts of Chlorophytum comosum were measured by MTT assay on breast cancer (MCF-7), lung cancer (A549 & H1299) and normal lung (L-132) cell lines. The toxicity studies of the extracts were carried out using Hemolysis assay. RESULTS: GC-MS analysis identified 34 metabolites in roots and 17 from leaves, while 17 compounds from roots and 7 from leaves were detected by LC-ESI-MS. Significant antiproliferative effects were observed on the A549 and MCF-7 cancer cell lines with IC50 values ranging from 56.86 µg/ml to 68.68 µg/ml while no marked response was observed against normal cell line L-132. CONCLUSION: Our study represents the first report on the detailed chemical composition and antiproliferative potential of Chlorophytum comosum against lung and breast cancer cell lines.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Asparagaceae/química , Neoplasias/tratamento farmacológico , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida , Ensaios de Seleção de Medicamentos Antitumorais , Radicais Livres/antagonistas & inibidores , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray
9.
Mol Biol Rep ; 47(10): 7655-7673, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32979167

RESUMO

The salinity stress tolerance in plants has been studied enormously, reflecting its agronomic relevance. Despite the extensive research, limited success has been achieved in relation to the plant tolerance mechanism. The beneficial interaction between Piriformospora indica and rice could essentially improve the performance of the plant during salt stress. In this study, the transcriptomic data between P. indica treated and untreated rice roots were compared under control and salt stress conditions. Overall, 661 salt-responsive differentially expressed genes (DEGs) were detected with 161 up- and 500 down-regulated genes in all comparison groups. Gene ontology analyses indicated the DEGs were mainly enriched in "auxin-activated signaling pathway", "water channel activity", "integral component of plasma membrane", "stress responses", and "metabolic processes". Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the DEGs were primarily related to "Zeatin biosynthesis", "Fatty acid elongation", "Carotenoid biosynthesis", and "Biosynthesis of secondary metabolites". Particularly, genes related to cell wall modifying enzymes (e.g. invertase/pectin methylesterase inhibitor protein and arabinogalactans), phytohormones (e.g. Auxin-responsive Aux/IAA gene family, ent-kaurene synthase, and 12-oxophytodienoate reductase) and receptor-like kinases (e.g. AGC kinase and receptor protein kinase) were induced in P. indica colonized rice under salt stress condition. The differential expression of these genes implies that the coordination between hormonal crosstalk, signaling, and cell wall dynamics contributes to the higher growth and tolerance in P. indica-inoculated rice. Our results offer a valuable resource for future functional studies on salt-responsive genes that should improve the resilience and adaptation of rice against salt stress.


Assuntos
Basidiomycota/metabolismo , Endófitos/metabolismo , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Oryza/microbiologia , Salinidade , Tolerância ao Sal
10.
Front Pharmacol ; 9: 23, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29441016

RESUMO

Modern diets containing high quantities of salt and cholesterol have exhibited to cause a considerable effect on our health. Such diets, when consumed in the long term, have also shown to be a precursor to several disorders such as the metabolic disorder and consequently, various other diseases, including cognitive deficits. In the present study, we used a high salt and cholesterol diet (HSCD) to induce cognitive impairment in rats and also investigated the pharmacological action of tannins enriched fractions of Emblica officinalis (EOT) - a fruit that has been traditionally used for the treatment of numerous disorders for centuries. Significant alterations in MDA, GSH, TBARS, GPx, mitochondrial ATP, and mitochondrial membrane potential levels were observed in rats fed HSCD, which indicated presence of oxidative stress. Moreover, classic signs of cognitive impairment and deficits in spatial learning and memory were observed in the neurobehavioral tests. E. officinalis tannins exhibited good affinity to Nrf2 receptors in in silico studies, significantly reversed the changes in the aforementioned biomarkers of oxidative stress which were altered in the model group, as well as improved the performance of rats in Morris water maze task. Our results also reflected that EOT supplementation significantly increased the expression of Nrf2 in the CA1 region of hippocampus and cortex. Additionally, TUNEL assay indicated that EOT supplementation led to reversal of DNA fragmentation and apoptosis caused by HSCD. Immunohistochemical analysis and western blot further revealed a surge in the nuclear location of Nrf2. Through our study, we have demonstrated that cognitive impairment can be caused in rats via HSCD as a result of the oxidative stress induced by the same. Additionally, we have investigated a novel mechanism of action for EOT (which strongly suggests to be via the Nrf2-ARE pathway) and demonstrated that it has the potential to be used in the treatment of cognitive impairment.

11.
Clin Exp Nephrol ; 22(3): 508-516, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29022109

RESUMO

BACKGROUND: The induction of CD80 on podocytes has been shown in animal models of podocyte injury and in certain cases of nephrotic syndrome. In a lipopolysaccharide (LPS)-induced mouse model of albuminuria, we have recently shown a signalling axis of LPS-myeloid cell activation-TNFα production-podocyte CD80 induction-albuminuria. Therefore, in this report, we investigated the cellular and molecular consequences of TNFα addition and CD80 expression on cultured podocytes. METHODS: A murine podocyte cell line was used for TNFα treatment and for over-expressing CD80. Expression and localization of various podocyte proteins was analysed by reverse transcriptase-polymerase chain reaction, western blotting and immunofluorescence. HEK293 cells were used to biochemically characterize interactions. RESULTS: Podocytes treated with LPS in vitro did not cause CD80 upregulation but TNFα treatment was associated with an increase in CD80 levels, actin derangement and poor wound healing. Podocytes stably expressing CD80 showed actin derangement and co-localization with Neph1. CD80 and Neph1 interaction was confirmed by pull down assays of CD80 and Neph1 transfected in HEK293 cells. CONCLUSION: Addition of TNFα to podocytes causes CD80 upregulation, actin reorganization and podocyte injury. Overexpressed CD80 and Neph1 interact via their extracellular domain. This interaction implies a mechanism of slit diaphragm disruption and possible use of small molecules that disrupt CD80-Neph1 interaction as a potential for treatment of nephrotic syndrome associated with CD80 upregulation.


Assuntos
Antígeno B7-1/metabolismo , Proteínas de Membrana/metabolismo , Síndrome Nefrótica/etiologia , Podócitos/fisiologia , Fator de Necrose Tumoral alfa/fisiologia , Actinas/metabolismo , Animais , Linhagem Celular , Células HEK293 , Humanos , Camundongos
12.
Sci Rep ; 7(1): 5255, 2017 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-28701714

RESUMO

Inorganic pyrophosphatases (PPase) participate in energy cycling and they are essential for growth and survival of organisms. Here we report extensive structural and functional characterization of soluble PPases from the human parasites Plasmodium falciparum (PfPPase) and Toxoplasma gondii (TgPPase). Our results show that PfPPase is a cytosolic enzyme whose gene expression is upregulated during parasite asexual stages. Cambialistic PfPPase actively hydrolyzes linear short chain polyphosphates like PPi, polyP3 and ATP in the presence of Zn2+. A remarkable new feature of PfPPase is the low complexity asparagine-rich N-terminal region that mediates its dimerization. Deletion of N-region has an unexpected and substantial effect on the stability of PfPPase domain, resulting in aggregation and significant loss of enzyme activity. Significantly, the crystal structures of PfPPase and TgPPase reveal unusual and unprecedented dimeric organizations and provide new fundamental insights into the variety of oligomeric assemblies possible in eukaryotic inorganic PPases.


Assuntos
Pirofosfatase Inorgânica/química , Pirofosfatase Inorgânica/metabolismo , Fosfotransferases/metabolismo , Plasmodium falciparum/enzimologia , Conformação Proteica , Toxoplasma/enzimologia , Sequência de Aminoácidos , Cristalografia por Raios X , Citosol/metabolismo , Pirofosfatase Inorgânica/genética , Modelos Moleculares , Fosfotransferases/química , Domínios Proteicos , Multimerização Proteica , Homologia de Sequência
13.
FEBS Open Bio ; 7(3): 367-381, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28286732

RESUMO

Water stress is one of the most critical abiotic stresses that restricts growth, development, and alters physiological and biochemical mechanisms of plant. The effects of long-term water shortage-induced oxidative stress on morphophysiological parameters, proline metabolic genes, and artemisinin content were studied in Artemisia annua L. under greenhouse conditions. Plant growth, biomass accumulation, relative water content, and chlorophyll content were reduced under drought. Leaf water potential ranged from -0.3248 MPa to -1.22 MPa in stress conditions. Increased levels of proline accumulation, protein concentration, and lipid peroxidation were detected in water-stressed plants. Stage-dependent increases in activity of antioxidants including superoxide dismutase, ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase, and dehydroascorbate reductase were observed. The expression of proline biosynthetic genes including pyrroline-5-carboxylase synthase1, 1-pyrroline-5-carboxylase synthase2, and 1-pyrroline-5-carboxylase reductase was induced, while the ornithine aminotransferase transcript showed a variable response and the expression of proline catabolic genes including proline dehydrogenase1, proline dehydrogenase1, and proline 5-carboxylate dehydrogenase was reduced by water stress. Our results indicate that the glutamine pathway is predominant under drought stress in A. annua and a reduction of catabolic gene expression is adopted as a defense strategy in adverse conditions. Higher expression of biosynthetic genes and lower expression of catabolic genes at the preflowering stage confirmed the important role of proline in flower development. Artemisinin content decreased owing to water stress, but the slightly higher amounts were detected in leaves of severely stressed plants compared with moderately stressed plants. The artemisinin content of A. annua might be regulated by controlling irrigation regimes.

14.
Plant Physiol Biochem ; 114: 19-28, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28249222

RESUMO

Ashwagandha (Withania somnifera) is one of the most reputed medicinal plants in the traditional medicinal system. In this study, cell suspension culture of W. somnifera was elicited with cell homogenates of fungi (A. alternata, F. solani, V. dahliae and P. indica) in shake flask and the major withanolides like withanolide A, withaferin A and withanone were analysed. Simultaneously expression levels of key pathway genes from withanolides biosynthetic pathways were also checked via quantitative PCR in shake flask as well as in bioreactor. The results show that highest gene expression of 10.8, 5.8, 4.9, and 3.3 folds were observed with HMGR among all the expressed genes in cell suspension cultures with cell homogenates of 3% P. indica, 5% V. dahliae, 3% A. alternata and 3% F. solani, respectively, in comparison to the control in shake flask. Optimized concentration of cell homogenate of P. indica (3% v/v) was added to the growing culture in 5.0-l bioreactor under optimized up-scaling conditions and harvested after 22 days. The genes of MVA, MEP and withanolides biosynthetic pathways like HMGR, SS, SE, CAS, FPPS, DXR and DXS were up-regulated by 12.5, 4.9, 2.18, 4.65, 2.34, 1.89 and 1.4 folds, respectively in bioreactor. The enhancement of biomass (1.13 fold) and withanolides [withanolide A (1.7), withaferin A (1.5), and withanone (1.5) folds] in bioreactor in comparison to shake flask was also found to be in line with the up-regulation of genes of withanolide biosynthetic pathways.


Assuntos
Técnicas de Cultura de Células/métodos , Withania/metabolismo , Withania/microbiologia , Vitanolídeos/metabolismo , Biomassa , Reatores Biológicos , Técnicas de Cultura de Células/instrumentação , Fungos/fisiologia , Regulação da Expressão Gênica de Plantas , Triterpenos/análise , Triterpenos/metabolismo , Withania/citologia , Withania/genética , Vitanolídeos/análise
15.
Artigo em Inglês | MEDLINE | ID: mdl-29387631

RESUMO

Dengue virus is a pathogen of global concern and has a huge impact on public health system in low- and middle-income countries. The capsid protein of dengue virus is least conserved among related flavivirus and there is very limited information on the role of cytosolic proteins that interact with dengue virus capsid. We identified DEAD (Asp-Glu-Ala-Asp) Box Helicase 3, an X-Linked (DDX3X), cytosolic ATP-dependent RNA helicase as a dengue virus capsid-interacting protein. We show that the N-terminal region of capsid is important for interaction with DDX3X, while the N-terminal domain of DDX3X seems to be involved in interaction with dengue capsid. DDX3X was down-regulated in dengue virus infected cells at later stages of infection. Our results show that DDX3X is an antiviral protein as suppression of DDX3X expression by siRNA led to an increase in viral titers and overexpression of DDX3X led to inhibition of viral replication. Knock-down of DDX3X did not affect induction of type I interferon response upon infection suggesting that the effect of DDX3X knock-down is independent of the interferon-dependent pathways that DDX3X modulates under normal conditions. Thus, our study identifies DDX3X as a dengue virus capsid interacting protein and indicates a potential link between the antiviral functions of DDX3X and dengue capsid at later stages of dengue infection.


Assuntos
Capsídeo/metabolismo , RNA Helicases DEAD-box/metabolismo , Vírus da Dengue/fisiologia , Dengue/metabolismo , Dengue/virologia , Interações Hospedeiro-Patógeno , Linhagem Celular , RNA Helicases DEAD-box/química , RNA Helicases DEAD-box/genética , Interações Hospedeiro-Patógeno/genética , Humanos , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Replicação Viral
16.
PLoS One ; 11(7): e0160035, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27466817

RESUMO

Short-chain fatty acids (SCFAs), such as butyric acid, have a broad range of applications in chemical and fuel industries. Worldwide demand of sustainable fuels and chemicals has encouraged researchers for microbial synthesis of SCFAs. In this study we compared three thioesterases, i.e., TesAT from Anaerococcus tetradius, TesBF from Bryantella formatexigens and TesBT from Bacteroides thetaiotaomicron, for production of SCFAs in Escherichia coli utilizing native fatty acid synthesis (FASII) pathway and modulated the genetic and bioprocess parameters to improve its yield and productivity. E. coli strain expressing tesBT gene yielded maximum butyric acid titer at 1.46 g L-1, followed by tesBF at 0.85 g L-1 and tesAT at 0.12 g L-1. The titer of butyric acid varied significantly depending upon the plasmid copy number and strain genotype. The modulation of genetic factors that are known to influence long chain fatty acid production, such as deletion of the fadD and fadE that initiates the fatty acid degradation cycle and overexpression of fadR that is a global transcriptional activator of fatty acid biosynthesis and repressor of degradation cycle, did not improve the butyric acid titer significantly. Use of chemical inhibitor cerulenin, which restricts the fatty acid elongation cycle, increased the butyric acid titer by 1.7-fold in case of TesBF, while it had adverse impact in case of TesBT. In vitro enzyme assay indicated that cerulenin also inhibited short chain specific thioesterase, though inhibitory concentration varied according to the type of thioesterase used. Further process optimization followed by fed-batch cultivation under phosphorous limited condition led to production of 14.3 g L-1 butyric acid and 17.5 g L-1 total free fatty acid at 28% of theoretical yield. This study expands our understanding of SCFAs production in E. coli through FASII pathway and highlights role of genetic and process optimization to enhance the desired product.


Assuntos
Ácido Butírico/metabolismo , Escherichia coli/genética , Ácidos Graxos Voláteis/metabolismo , Esterases/metabolismo , Ácidos Graxos Voláteis/biossíntese
17.
J Nanobiotechnology ; 14(1): 49, 2016 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-27334743

RESUMO

BACKGROUND: Engineering microorganisms in order to improve the metabolite flux needs a detailed knowledge of the concentrations and flux rates of metabolites and metabolic intermediates in vivo. Fluorescence resonance energy transfer (FRET) based genetically encoded nanosensors represent a promising tool for measuring the metabolite levels and corresponding rate changes in live cells. Here, we report the development of a series of FRET based genetically encoded nanosensor for real time measurement of lysine at cellular level, as the improvement of microbial strains for the production of L-lysine is of major interest in industrial biotechnology. RESULTS: The lysine binding periplasmic protein (LAO) from Salmonella enterica serovar typhimurium LT2 strain was used as the reporter element for the sensor. The LAO was sandwiched between GFP variants i.e. cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP). Affinity, pH stability, specificity and metal ions effects was scrutinized for the in vitro characterization of this nanosensor, named as FLIPK. The FLIPK is specific to lysine and found to be stable with the pH within the physiological range. The calculated affinity (K d ) of FLIPK was 97 µM. For physiological applications, mutants with different binding affinities were also generated and investigated in vitro. The developed nanosensor efficiently monitored the intracellular level of lysine in bacterial as well as yeast cell. CONCLUSION: The developed novel lysine fluorescence resonance energy transfer sensors can be used for in vivo monitoring of lysine levels in prokaryotes as well as eukaryotes. The potential of these sensors is that they can be used as reporter tools in the development of metabolically engineered microbial strains or for real-time monitoring of intracellular lysine during fermentation.


Assuntos
Proteínas de Bactérias/metabolismo , Técnicas Biossensoriais/métodos , Transferência Ressonante de Energia de Fluorescência/métodos , Lisina/análise , Imagem Óptica/métodos , Saccharomyces cerevisiae/citologia , Salmonella typhi/metabolismo , Proteínas de Bactérias/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Corantes Fluorescentes/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Lisina/metabolismo , Modelos Moleculares , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo , Salmonella typhi/genética
19.
Rev Med Virol ; 26(2): 129-41, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26695690

RESUMO

The mosquito-borne flavivirus, Japanese encephalitis virus (JEV), is the leading cause of virus-induced encephalitis globally and a major public health concern of several countries in Southeast Asia, with the potential to become a global pathogen. The virus is neurotropic, and the disease ranges from mild fever to severe hemorrhagic and encephalitic manifestations and death. The early steps of the virus life cycle, binding, and entry into the cell are crucial determinants of infection and are potential targets for the development of antiviral therapies. JEV can infect multiple cell types; however, the key receptor molecule(s) still remains elusive. JEV also has the capacity to utilize multiple endocytic pathways for entry into cells of different lineages. This review not only gives a comprehensive update on what is known about the virus attachment and receptor system (allies) and the endocytic pathways (alleys) exploited by the virus to gain entry into the cell and establish infection but also discusses crucial unresolved issues. We also highlight common themes and key differences between JEV and other flaviviruses in these contexts.


Assuntos
Vírus da Encefalite Japonesa (Espécie)/patogenicidade , Encefalite Japonesa/patologia , Receptores Virais/metabolismo , Proteínas do Envelope Viral/metabolismo , Ligação Viral , Internalização do Vírus , Encefalite Japonesa/virologia , Humanos , Replicação Viral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA