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1.
Plant Phenomics ; 6: 0174, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38629080

RESUMO

The deployment of intelligent surveillance systems to monitor tomato plant growth poses substantial challenges due to the dynamic nature of disease patterns and the complexity of environmental conditions such as background and lighting. In this study, an integrated cascade framework that synergizes detectors and trackers was introduced for the simultaneous identification of tomato leaf diseases and fruit counting. We applied an autonomous robot with smartphone camera to collect images for leaf disease and fruits in greenhouses. Further, we improved the deep learning network YOLO-TGI by incorporating Ghost and CBAM modules, which was trained and tested in conjunction with premier lightweight detection models like YOLOX and NanoDet in evaluating leaf health conditions. For the cascading with various base detectors, we integrated state-of-the-art trackers such as Byte-Track, Motpy, and FairMot to enable fruit counting in video streams. Experimental results indicated that the combination of YOLO-TGI and Byte-Track achieved the most robust performance. Particularly, YOLO-TGI-N emerged as the model with the least computational demands, registering the lowest FLOPs at 2.05 G and checkpoint weights at 3.7 M, while still maintaining a mAP of 0.72 for leaf disease detection. Regarding the fruit counting, the combination of YOLO-TGI-S and Byte-Track achieved the best R2 of 0.93 and the lowest RMSE of 9.17, boasting an inference speed that doubles that of the YOLOX series, and is 2.5 times faster than the NanoDet series. The developed network framework is a potential solution for researchers facilitating the deployment of similar surveillance models for a broad spectrum of fruit and vegetable crops.

2.
J Colloid Interface Sci ; 661: 700-708, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38320406

RESUMO

The incorporation of high-valence transition metal atoms into FeNi (oxy)hydroxides may be a promising strategy to regulate the intrinsic electronic states, thereby reducing the thermodynamic barrier and accelerating oxygen evolution reaction (OER). Here, a high-valence Mo atoms doping route is proposed by an efficient self-reconstruction strategy to prepare MoFeNi (oxy)hydroxides for efficient alkaline OER. By using borides (MoNiB) as sacrificial template and Mo source, FeNi (oxy)hydroxides nanoflakes embedded with high-valence Mo atoms (MoFeNi) is successfully synthesized, which can modulate the electron coordination to improve the intrinsic catalytic activity. Remarkably, the obtained MoFeNi exhibits extremely low overpotential (η100 = 252 mV and η500 = 288 mV) and small Tafel slope (18.35 mV dec-1). The robust catalyst can run stably for hours at 500 mA cm-2. Characterization results and theoretical calculations confirmed that the addition of high-valence Mo effectively modulated the intrinsic electronic structure of metal sites and optimized the adsorption/desorption energy of the intermediates, accelerating OER reactions kinetics. By coupling MoFeNi anode with Pt/C cathode, anion exchange membrane (AEM) electrolyser can operate stably at 500 mA cm-2 with about less than 2.2 V. This research introduces a novel approach to develop ideal electrocatalysts through the incorporation of high-valence molybdenum species.

3.
Plants (Basel) ; 12(15)2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37570986

RESUMO

Light-emitting diodes (LEDs) have been widely used as light sources for plant production in plant factories with artificial lighting (PFALs), and light spectrum and light amount have great impacts on plant growth and development. With the expansion of the product list of PFALs, tomato production in PFALs has received attention, but studies on fruit quality influenced by artificial light are lacking. In this study, precisely modulated LED light sources based on white light combined with additional red, blue, and green lights were used to investigate the effects of light spectrum and daily light integral (DLI) on the main quality indicators and flavor substances of "Micro-Tom" tomato fruits. The highest sugar-acid ratio was obtained under the white light with addition of red light with high DLI and blue light with low DLI. The contents of ß-carotene, lycopene, and lutein were significantly increased by higher DLI conditions except for under the blue light treatment, and the cross-interactions between the light spectrum and DLI were observed. The accumulation of the main flavor substances in tomato fruits was decreased by addition of green light with a high DLI and red light with a low DLI; notably, the percentage of 2-isobutylthiazole, which is associated with fresh tomato aroma, was decreased by green light. This study provides insights for improving tomato fruit quality and flavor by regulating light conditions in PFALs.

4.
HIV Med ; 23 Suppl 1: 95-105, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35293098

RESUMO

OBJECTIVES: The emergence of pretreatment drug resistance (PDR) caused by increased usage of antiretroviral therapy (ART) represents a significant challenge to HIV management. In this study, we evaluated the prevalence of PDR in people living with HIV (PLWH) in Chongqing, China. METHODS: We retrospectively collected the data of 1110 ART-naïve PLWH in Chongqing from January 1, 2018 to June 30, 2021. HIV-1 genotypes and drug resistance were analyzed using the HIV-1 pol sequence. Risk factors associated with PDR were evaluated via the logistic regression model. RESULTS: Nine genotypes were detected among 1110 participants, with CRF07_BC (55.68%) being the dominant genotype, followed by CRF01_AE (21.44%), CRF08_BC (14.14%), and other genotypes (8.74%). Of all the participants, 24.14% exhibited drug resistance mutations (DRMs). The predominant DRMs for non-nucleoside reverse transcriptase inhibitors (NNRTIs) and nucleoside reverse transcriptase inhibitors (NRTIs) were V179D/E/A/DIN (13.60%) and M184V/I (1.44%), respectively, whereas only two major DRMs (M46L and I54L) were identified for protease inhibitors (PIs). The total prevalence of PDR was 10.54%, with 2.43%, 7.66%, and 1.71% participants exhibiting PDR to NRTIs, NNRTIs, and PIs, respectively. Furthermore, female PLWH, delays in ART initiation, and the CRF08_BC genotype were associated with a higher risk of PDR. CONCLUSIONS: Our study provides the first large cohort data on the prevalence of PDR in Chongqing, China. HIV-1 genotypes are diverse and complex, with a moderate level of PDR, which does not reach the threshold for the initiation of a public health response. Nevertheless, continuous surveillance of PDR is both useful and advisable.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , China/epidemiologia , Farmacorresistência Viral/genética , Feminino , Genótipo , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Humanos , Mutação , Prevalência , Estudos Retrospectivos , Inibidores da Transcriptase Reversa/farmacologia
5.
J Colloid Interface Sci ; 614: 84-91, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35091149

RESUMO

CoP is one of the most promising catalysts for catalyzing hydrogen evolution reaction. The foremost issue is how to improve intrinsic activity by regulating electronic structure at the molecular level. Herein, utilizing selective combination of EDTA and Co2+, an amorphous-crystalline CoP with lower valence cobalt and hollow porous structure which induced by dual ligand environment is successfully synthesized via microwave heating and following phosphating process. Synthesize CoPBA from EDTA3+ and Co3+ in a ratio of 1:1 and followed by phosphating (ECP-1) exhibits excellent performance for HER in alkaline media, requiring 173 mV to achieve 10 mA cm-2. The enhanced catalytic activity may be ascribed to the amorphous-crystalline crystal structure with enlarged exposure of active sites and the hollow porous framework induced by EDTA, as well as the homogeneously distribution of (111) plane, on which the change of free energy on both Co bridge sites and P top sites is close to zero when adsorbing hydrogen. Besides, its great catalytic stability has been evaluated via 1000 cycles of CV measurement. The possible mechanism of valence state regulation of cobalt ions in CoP is discussed in detail. Furthermore, the optimal ratio of EDTA to Co2+ and different precursor states are explored reasonably.

6.
J Colloid Interface Sci ; 610: 173-181, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34922073

RESUMO

The incorporation of borate is a beneficial strategy to improve the catalytic activity of transition metal-based electrocatalyts for oxygen evolution reaction (OER). However, how to efficiently introduce borate has always been a challenge. Here, a facile and scalable molten salt method is developed to successfully dope borate into FeNi layered double hydroxides (FeBi@FeNi LDH) for efficient OER. The molten salt method can not only promote the formation of evenly dispersed nano-pompous FeBi precursor, thus providing the possibility to realize the direct doping of borate and the increase of mass, charge transfer and oxygen evolution active sites in FeNi LDH, but also promote the in-situ growth of FeBi@FeNi LDH on the conductive iron foam, improvingconductivity and stability of the material. The results indicate that the synthesized FeBi@FeNi LDH shows enhanced OER activity by delivering current densities of 10 and 100 mA cm-2 at low overpotentials of 246 and 295 mV and showing a small Tafel slope of 56.48 mV dec-1, benefiting from the optimization of geometric structure of active sites as well as the adjustment of electron density by borate doping especially in the case of molten salt. In addition, the sample can maintain durability at an industrial current density of 100 mA cm-1 for 90 h. This work provides a new way for the construction of efficient catalysts using boron doping assisted by molten salt.

7.
Artigo em Inglês | MEDLINE | ID: mdl-34853599

RESUMO

Jinwujiangu capsule (JWJGC) is a traditional Chinese medicine formula used to treat rheumatoid arthritis (RA). However, whether its mechanism is associated with pyroptosis remains unclear. In this study, the ability of JWJGC to inhibit the growth of fibroblast-like synoviocytes of RA (RA-FLS) through pyroptosis was evaluated. The cells isolated from patients with RA were identified by hematoxylin and eosin (H&E) staining, immunohistochemistry, and flow cytometry. After RA-FLS were treated with different concentrations of JWJGC-containing serum, the cell proliferation inhibition rate, expression of caspase-1/3/4/5, NOD-like receptor protein 3 (NLRP3), gasdermin-D (GSDMD), and apoptosis-associated speck-like protein containing a CARD (ASC), concentrations of interleukin-1ß (IL-1ß) and interleukin-18 (IL-18), the activity of lactic dehydrogenase (LDH), and pyroptosis were evaluated. The results showed that JWJGC increased the proliferative inhibition rate, decreased the expression of caspase-1/3/4/5, GSDMD, NLRP3, and ASC, suppressed the expression of IL-1ß and IL-18, induced the activity of LDH, and downregulated the number of double-positive FITC anti-caspase-1 and PI. Generally, our findings suggest that JWJGC can regulate NLRP3/CAPSES/GSDMD in treating RA-FLS through pyroptosis.

8.
Drug Deliv ; 28(1): 1007-1019, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34060401

RESUMO

Background: Pulmonary arterial hypertension (PAH) is a severe and fatal clinical syndrome characterized by high blood pressure and vascular remodeling in the pulmonary arterioles, which is also a rapidly progressing disease of the lung vasculature with a poor prognosis. Although PAH medication made great advances in recent years, the efficacy and safety of the medication are unsatisfactory. Therefore, we aimed to update and expand previous studies to explore the efficacy and safety of PAH-targeted medications. Methods: Relevant articles were searched and selected from published or publicly available data in PubMed, Cochrane Library, CNKI, PsycInfo, and MEDLINE (from inception until October 1st, 2020). To assess the efficacy and safety of PAH therapies, five efficacy outcomes [6-minute walking distance (6MWD), mean pulmonary arterial pressure (mPAP), WHO functional class (WHO FC) improvement, clinical worsening, death] and two safety outcomes [adverse events (AEs), serious adverse events (SAEs)] were selected. And 6MWD was regarded as the primary efficacy outcome.Results: 50 trials included with 10 996participants were selected. In terms of efficacy, all targeted drugs were more effective than placebo. For 6MWD, Bosentan + Sildenafil, Sildenafil, Bosentan + Iloprost were better than others. Bosentan + Iloprost and Bosentan + Sildenafil were better for mPAP. Bosentan + Iloprost and Ambrisentan + Tadalafil were more effective in improving WHO FC. Bosentan + Tadalafil and Bosentan + Iloprost had the Ambrisentan probability to reduce the incidence of clinical worsening. It is demonstrated that Ambrisentan had clear benefits in reducing all-cause mortality. In terms of safety, no therapies had been shown to reduce the incidence of SAEs significantly, and Ambrisentan + Tadalafil significantly increased the incidence of AEs.Conclusions: Phosphodiesterase 5 inhibitor (PDE5i) + Endothelin Receptor Antagonists (ERA) seems to be better therapy for PAH. Prostacyclin analogs (ProsA) + ERA appear promising, though additional data is warranted.Registration PROSPERO CRD42020218818.


Assuntos
Anti-Hipertensivos/uso terapêutico , Hipertensão Arterial Pulmonar/tratamento farmacológico , Vasodilatadores/uso terapêutico , Teorema de Bayes , Progressão da Doença , Quimioterapia Combinada , Humanos , Metanálise em Rede , Ensaios Clínicos Controlados Aleatórios como Assunto , Índice de Gravidade de Doença , Teste de Caminhada
9.
Artigo em Inglês | MEDLINE | ID: mdl-31330992

RESUMO

Greenhouse cultivation consumes large volumes of freshwater, and excessive irrigation induces environmental problems, such as nutrient leaching and secondary salinization. Pyrochar (biochar from high-temperature pyrolysis) is an effective soil amendment, and researches have shown that pyrochar application could maintain soil nutrient and enhance carbon sequestration. In addition to pyrochar from pyrolysis, hydrochar from hydrothermic carbonization is considered as a new type of biochar and has the advantages of low energy consumption and a high productive rate. However, the effect of these two biochars on water evaporation in clayey soils under a greenhouse system has seldom been studied. The relationship between water evaporation and biochar properties is still unknown. Thus, in the present study, water evaporation under pyrochar and hydrochar application were recorded. Results showed that both pyrochar and hydrochar application could inhibit water evaporation in clayey soil under greenhouse cultivation. Pyrochar showed a better inhibition effect compared with hydrochar. Correlation analysis indicated that the water evaporation rate was significantly positively correlated with bulk density of biochar (p < 0.05). Overall, application of pyrochar or hydrochar could both reduce soil bulk density and inhibit soil evaporation, and be available for greenhouse cultivation. However, the inhibition effect depends on the properties of the biochar.


Assuntos
Carvão Vegetal/química , Horticultura , Água/química , Carbono/química , Sequestro de Carbono , Argila/química , Solo/química , Volatilização
10.
Front Microbiol ; 7: 1605, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27790202

RESUMO

The aim of this study was to reveal the molecular mechanism involved in multidrug resistance and virulence of Campylobacter jejuni isolated from broiler chickens. The virulence of six multidrug resistant C. jejuni was determined by in vitro and in vivo methods. The de novo whole genome sequencing technology and molecular biology methods were used to analyze the genomic features associated with the multidrug resistance and virulence of a selected isolate (C. jejuni 1655). The comparative genomic analyses revealed a large number of single nucleotide polymorphisms, deletions, rearrangements, and inversions in C. jejuni 1655 compared to reference C. jejuni genomes. The co-emergence of Thr-86-Ile mutation in gyrA gene, A2075G mutation in 23S rRNA gene, tetO, aphA and aadE genes and pTet plasmid in C. jejuni 1655 contributed its multidrug resistance to fluoroquinolones, macrolides, tetracycline, and aminoglycosides. The combination of multiple virulence genes may work together to confer the relative higher virulence in C. jejuni 1655. The co-existence of mobile gene elements (e.g., pTet) and CRISPR-Cas system in C. jejuni 1655 may play an important role in the gene transfer and immune defense. The present study provides basic information of phenotypic and genomic features of C. jejuni 1655, a strain recently isolated from a chicken displaying multidrug resistance and relatively high level of virulence.

11.
Sci Rep ; 6: 24255, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-27052100

RESUMO

Phosphopantetheinyl transferases (PPTases) play essential roles in both primary metabolisms and secondary metabolisms via post-translational modification of acyl carrier proteins (ACPs) and peptidyl carrier proteins (PCPs). In this study, an industrial FK506 producing strain Streptomyces tsukubaensis L19, together with Streptomyces avermitilis, was identified to contain the highest number (five) of discrete PPTases known among any species thus far examined. Characterization of the five PPTases in S. tsukubaensis L19 unveiled that stw ACP, an ACP in a type II PKS, was phosphopantetheinylated by three PPTases FKPPT1, FKPPT3, and FKACPS; sts FAS ACP, the ACP in fatty acid synthase (FAS), was phosphopantetheinylated by three PPTases FKPPT2, FKPPT3, and FKACPS; TcsA-ACP, an ACP involved in FK506 biosynthesis, was phosphopantetheinylated by two PPTases FKPPT3 and FKACPS; FkbP-PCP, an PCP involved in FK506 biosynthesis, was phosphopantetheinylated by all of these five PPTases FKPPT1-4 and FKACPS. Our results here indicate that the functions of these PPTases complement each other for ACPs/PCPs substrates, suggesting a complicate phosphopantetheinylation network in S. tsukubaensis L19. Engineering of these PPTases in S. tsukubaensis L19 resulted in a mutant strain that can improve FK506 production.


Assuntos
Proteínas de Bactérias/metabolismo , Redes e Vias Metabólicas , Streptomyces/enzimologia , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo , Proteína de Transporte de Acila/genética , Proteína de Transporte de Acila/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Cromatografia Líquida de Alta Pressão , Fermentação , Genoma Bacteriano/genética , Espectrometria de Massas , Família Multigênica , Mutação , Homologia de Sequência de Aminoácidos , Streptomyces/genética , Streptomyces/metabolismo , Tacrolimo/metabolismo , Transferases (Outros Grupos de Fosfato Substituídos)/genética
12.
FEBS J ; 282(13): 2527-39, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25865045

RESUMO

UNLABELLED: Acyltransferase (AT) domains of polyketide synthases (PKSs) usually use coenzyme A (CoA) as an acyl donor to transfer common acyl units to acyl carrier protein (ACP) domains, initiating incorporation of acyl units into polyketides. Two clinical immunosuppressive agents, FK506 and FK520, are biosynthesized by the same PKSs in several Streptomyces strains. In this study, characterization of AT4FkbB (the AT domain of the fourth module of FK506 PKS) in transacylation reactions showed that AT4FkbB recognizes both an ACP domain (ACPT csA) and CoA as acyl donors for transfer of a unique allylmalonyl (AM) unit to an acyl acceptor ACP domain (ACP4FkbB), resulting in FK506 production. In addition, AT4FkbB uses CoA as an acyl donor to transfer an unusual ethylmalonyl (EM) unit to ACP4FkbB, resulting in FK520 production, and transfers AM units to non-native ACP acceptors. Characterization of AT4FkbB in self-acylation reactions suggests that AT4FkbB controls acyl unit specificity in transacylation reactions but not in self-acylation reactions. Generally, AT domains of PKSs only recognize one acyl donor; however, we report here that AT4FkbB recognizes two acyl donors for the transfer of different acyl units. DATABASE: Nucleotide sequence data have been submitted to the GenBank database under accession numbers KJ000382 and KJ000383.


Assuntos
Proteína de Transporte de Acila/química , Aciltransferases/química , Coenzima A/química , Policetídeo Sintases/química , Tacrolimo/metabolismo , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Dados de Sequência Molecular , Família Multigênica , Estrutura Terciária de Proteína , Streptomyces/metabolismo , Especificidade por Substrato
13.
Curr Microbiol ; 70(3): 390-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25413605

RESUMO

It is known that bacterial group II phosphopantetheinyl transferases (PPTases) usually phosphopantetheinylate acyl carrier proteins (ACPs) involved in the secondary metabolism. For example, a bacterial group II PPTase SchPPT has been known to phosphopantetheinylate only ACPs involved in secondary metabolism, such as scn ACP0-2 and scn ACP7. In this study, we found two bacterial group II PPTases, Hppt and Sppt, could phosphopantetheinylate not only scn ACP0-2 and scn ACP7, but also sch FAS ACP, an ACP involved in primary metabolism. Swapping of the N terminus and C terminus of PPTases showed that (i) both the hybrids Hppt-Sppt and Sppt-Hppt could phosphopantetheinylate sch FAS ACP but not scn ACP0-2; (ii) both the hybrids Sppt-SchPPT and SchPPT-Sppt lost abilities to phosphopantetheinylate sch FAS ACP and scn ACP0-2. Hppt and Sppt represent group II PPTases which phosphopantetheinylate both ACPs involved in primary metabolism and ACPs involved in secondary metabolism.


Assuntos
Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Metabolismo Basal , Metabolismo Secundário , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo , Sequência de Aminoácidos , Bactérias/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Catálise , Ativação Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Dados de Sequência Molecular , Filogenia , Domínios e Motivos de Interação entre Proteínas , Transferases (Outros Grupos de Fosfato Substituídos)/química , Transferases (Outros Grupos de Fosfato Substituídos)/genética
14.
PLoS One ; 9(7): e103031, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25036863

RESUMO

Phosphopantetheinyl transferases (PPTases), which play an essential role in both primary and secondary metabolism, are magnesium binding enzymes. In this study, we characterized the magnesium binding residues of all known group II PPTases by biochemical and evolutionary analysis. Our results suggested that group II PPTases could be classified into two subgroups, two-magnesium-binding-residue-PPTases containing the triad Asp-Xxx-Glu and three-magnesium-binding-residue-PPTases containing the triad Asp-Glu-Glu. Mutations of two three-magnesium-binding-residue-PPTases and one two-magnesium-binding-residue-PPTase indicate that the first and the third residues in the triads are essential to activities; the second residues in the triads are non-essential. Although variations of the second residues in the triad Asp-Xxx-Glu exist throughout the whole phylogenetic tree, the second residues are conserved in animals, plants, algae, and most prokaryotes, respectively. Evolutionary analysis suggests that: the animal group II PPTases may originate from one common ancestor; the plant two-magnesium-binding-residue-PPTases may originate from one common ancestor; the plant three-magnesium-binding-residue-PPTases may derive from horizontal gene transfer from prokaryotes.


Assuntos
Proteínas de Bactérias/genética , Dipeptídeos/genética , Transferases (Outros Grupos de Fosfato Substituídos)/genética , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , Sítios de Ligação/genética , Evolução Biológica , Magnésio/metabolismo , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo
15.
Gene ; 544(2): 208-15, 2014 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-24768321

RESUMO

Daptomycin, a novel cyclic lipopeptide antibiotic against Gram-positive bacteria, is produced by Streptomyces roseosporus. Though its biosynthetic mechanism, structural shuffling and fermentation optimization have been extensively studied, little is understood about its production regulation at the transcriptional levels. Here we reported that dptR2, encoding a DeoR-type regulator located close to the daptomycin biosynthesis gene cluster in S. roseosporus SW0702, is required for daptomycin production, but not for the expression of daptomycin gene cluster, suggesting that DptR2 was not a pathway-specific regulator. Furthermore, EMSA and qRT-PCR analysis suggested that DptR2 was positively auto-regulated by binding to its own promoter. Meanwhile, the binding sites on the dptR2 promoter were determined by a DNase I footprinting assay, and the essentiality of the inverted complementary sequences in the protected region for DptR2 binding was assessed. Our results for the first time reported the regulation of daptomycin production at the transcriptional level in S. roseosporus.


Assuntos
Proteínas de Bactérias/metabolismo , Daptomicina/biossíntese , Regulação Bacteriana da Expressão Gênica/genética , Regiões Promotoras Genéticas , Proteínas Repressoras/metabolismo , Streptomyces/genética , Proteínas de Bactérias/genética , Sequência de Bases , Sítios de Ligação/genética , Dados de Sequência Molecular , Ligação Proteica/genética , Proteínas Repressoras/genética , Streptomyces/metabolismo , Transcrição Gênica
16.
FEBS Lett ; 588(4): 608-13, 2014 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-24440356

RESUMO

In Streptomyces coelicolor, the ECF sigma factor SigT negatively regulates cell differentiation, and is degraded by ClpP protease in a dual positive feedback manner. Here we further report that the proteasome is required for degradation of SigT, but not for degradation of its anti-sigma factor RstA, and RstA can protect SigT from degradation independent of the proteasome. Meanwhile, deletion of the proteasome showed reduced production of secondary metabolites, and the fermentation medium from wild type could promote SigT degradation. Furthermore, overexpression of redD or actII-orf4 in the proteasome-deficiency mutant resulted in SigT degradation and over-production of both undecylprodigiosin and actinorhodin. Therefore the proteasome is required for SigT degradation by affecting the production of secondary metabolites during cell differentiation.


Assuntos
Proteínas de Bactérias/metabolismo , Diferenciação Celular , Complexo de Endopeptidases do Proteassoma/metabolismo , Fator sigma/metabolismo , Streptomyces coelicolor/citologia , Streptomyces coelicolor/metabolismo , Antraquinonas/metabolismo , Prodigiosina/análogos & derivados , Prodigiosina/biossíntese , Proteólise
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