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1.
Nature ; 611(7935): 326-331, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36174646

RESUMO

The Toll/interleukin-1 receptor (TIR) domain is a key component of immune receptors that identify pathogen invasion in bacteria, plants and animals1-3. In the bacterial antiphage system Thoeris, as well as in plants, recognition of infection stimulates TIR domains to produce an immune signalling molecule whose molecular structure remains elusive. This molecule binds and activates the Thoeris immune effector, which then executes the immune function1. We identified a large family of phage-encoded proteins, denoted here as Thoeris anti-defence 1 (Tad1), that inhibit Thoeris immunity. We found that Tad1 proteins are 'sponges' that bind and sequester the immune signalling molecule produced by TIR-domain proteins, thus decoupling phage sensing from immune effector activation and rendering Thoeris inactive. Tad1 can also efficiently sequester molecules derived from a plant TIR-domain protein, and a high-resolution crystal structure of Tad1 bound to a plant-derived molecule showed a unique chemical structure of 1 ''-2' glycocyclic ADPR (gcADPR). Our data furthermore suggest that Thoeris TIR proteins produce a closely related molecule, 1''-3' gcADPR, which activates ThsA an order of magnitude more efficiently than the plant-derived 1''-2' gcADPR. Our results define the chemical structure of a central immune signalling molecule and show a new mode of action by which pathogens can suppress host immunity.


Assuntos
Bactérias , Bacteriófagos , Domínios Proteicos , Receptores de Interleucina-1 , Transdução de Sinais , Receptores Toll-Like , Proteínas Virais , Bactérias/imunologia , Bactérias/metabolismo , Bactérias/virologia , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/química , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/química , Proteínas de Plantas/imunologia , Proteínas de Plantas/metabolismo , Receptores de Interleucina-1/química , Transdução de Sinais/imunologia , Bacteriófagos/química , Bacteriófagos/imunologia , Bacteriófagos/metabolismo , Proteínas Virais/química , Proteínas Virais/imunologia , Proteínas Virais/metabolismo , Receptores Toll-Like/química , Cristalografia por Raios X
2.
Int J Mol Sci ; 22(23)2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34884830

RESUMO

The RING-type E3 ubiquitin ligases play an important role in plant growth, development, and defense responses to abiotic stresses and pathogens. However, their roles in the resistance of plants to herbivorous insects remain largely unknown. In this study, we isolated the rice gene OsJMJ715, which encodes a RING-domain containing protein, and investigated its role in rice resistance to brown planthopper (BPH, Nilaparvata lugens). OsJMJ715 is a nucleus-localized E3 ligase whose mRNA levels were upregulated by the infestation of gravid BPH females, mechanical wounding, and treatment with JA or ABA. Silencing OsJMJ715 enhanced BPH-elicited levels of ABA, JA, and JA-Ile as well as the amount of callose deposition in plants, which in turn increased the resistance of rice to BPH by reducing the feeding of BPH and the hatching rate of BPH eggs. These findings suggest that OsJMJ715 negative regulates the BPH-induced biosynthesis of ABA, JA, and JA-Ile and that BPH benefits by enhancing the expression of OsJMJ715.


Assuntos
Ácido Abscísico/metabolismo , Ciclopentanos/metabolismo , Hemípteros/fisiologia , Oryza/metabolismo , Oxilipinas/metabolismo , Proteínas de Plantas/genética , Ubiquitina-Proteína Ligases/genética , Ácido Abscísico/farmacologia , Animais , Ciclopentanos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glucanos/metabolismo , Herbivoria , Isoleucina/análogos & derivados , Isoleucina/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/parasitologia , Oxilipinas/farmacologia , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/parasitologia , Interferência de RNA , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Ubiquitina-Proteína Ligases/metabolismo
3.
PLoS One ; 16(10): e0258685, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34648605

RESUMO

To estimate the prevalence of herbicide-resistant weeds, 87 wheat and barley farms were randomly surveyed in the Canterbury region of New Zealand. Over 600 weed seed samples from up to 10 mother plants per taxon depending on abundance, were collected immediately prior to harvest (two fields per farm). Some samples provided by agronomists were tested on an ad-hoc basis. Over 40,000 seedlings were grown to the 2-4 leaf stage in glasshouse conditions and sprayed with high priority herbicides for grasses from the three modes-of-action acetyl-CoA carboxylase (ACCase)-inhibitors haloxyfop, fenoxaprop, clodinafop, pinoxaden, clethodim, acetolactate synthase (ALS)-inhibitors iodosulfuron, pyroxsulam, nicosulfuron, and the 5-enolpyruvyl shikimate 3-phosphate synthase (EPSPS)-inhibitor glyphosate. The highest manufacturer recommended label rates were applied for the products registered for use in New Zealand, often higher than the discriminatory rates used in studies elsewhere. Published studies of resistance were rare in New Zealand but we found weeds survived herbicide applications on 42 of the 87 (48%) randomly surveyed farms, while susceptible reference populations died. Resistance was found for ALS-inhibitors on 35 farms (40%) and to ACCase-inhibitors on 20 (23%) farms. The number of farms with resistant weeds (denominator is 87 farms) are reported for ACCase-inhibitors, ALS-inhibitors, and glyphosate respectively as: Avena fatua (9%, 1%, 0% of farms), Bromus catharticus (0%, 2%, 0%), Lolium spp. (17%, 28%, 0%), Phalaris minor (1%, 6%, 0%), and Vulpia bromoides (0%, not tested, 0%). Not all farms had the weeds present, five had no obvious weeds prior to harvest. This survey revealed New Zealand's first documented cases of resistance in P. minor (fenoxaprop, clodinafop, iodosulfuron) and B. catharticus (pyroxsulam). Twelve of the 87 randomly sampled farms (14%) had ALS-inhibitor chlorsulfuron-resistant sow thistles, mostly Sonchus asper but also S. oleraceus. Resistance was confirmed in industry-supplied samples of the grasses Digitaria sanguinalis (nicosulfuron, two maize farms), P. minor (iodosulfuron, one farm), and Lolium spp. (cases included glyphosate, haloxyfop, pinoxaden, iodosulfuron, and pyroxsulam, 9 farms). Industry also supplied Stellaria media samples that were resistant to chlorsulfuron and flumetsulam (ALS-inhibitors) sourced from clover and ryegrass fields from the North and South Island.


Assuntos
Inibidores Enzimáticos/farmacologia , Resistência a Herbicidas , Herbicidas/farmacologia , Hordeum/crescimento & desenvolvimento , Plantas Daninhas/crescimento & desenvolvimento , Triticum/crescimento & desenvolvimento , 3-Fosfoshikimato 1-Carboxiviniltransferase/antagonistas & inibidores , Acetolactato Sintase/antagonistas & inibidores , Acetil-CoA Carboxilase/antagonistas & inibidores , Fazendas , Nova Zelândia , Proteínas de Plantas/antagonistas & inibidores , Plantas Daninhas/classificação , Plantas Daninhas/enzimologia
4.
Viruses ; 13(9)2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34578418

RESUMO

In plants, HEN1-facilitated methylation at 3' end ribose is a critical step of small-RNA (sRNA) biogenesis. A mutant of well-studied Arabidopsis HEN1 (AtHEN1), hen1-1, showed a defective developmental phenotype, indicating the importance of sRNA methylation. Moreover, Marchantia polymorpha has been identified to have a HEN1 ortholog gene (MpHEN1); however, its function remained unfathomed. Our in vivo and in vitro data have shown MpHEN1 activity being comparable with AtHEN1, and their substrate specificity towards duplex microRNA (miRNA) remained consistent. Furthermore, the phylogenetic tree and multiple alignment highlighted the conserved molecular evolution of the HEN1 family in plants. The P1/HC-Pro of the turnip mosaic virus (TuMV) is a known RNA silencing suppressor and inhibits HEN1 methylation of sRNAs. Here, we report that the HC-Pro physically binds with AtHEN1 through FRNK motif, inhibiting HEN1's methylation activity. Moreover, the in vitro EMSA data indicates GST-HC-Pro of TuMV lacks sRNA duplex-binding ability. Surprisingly, the HC-Pro also inhibits MpHEN1 activity in a dosage-dependent manner, suggesting the possibility of interaction between HC-Pro and MpHEN1 as well. Further investigations on understanding interaction mechanisms of HEN1 and various HC-Pros can advance the knowledge of viral suppressors.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/virologia , Cisteína Endopeptidases/metabolismo , Marchantia/metabolismo , Metiltransferases/metabolismo , MicroRNAs/metabolismo , RNA de Plantas/metabolismo , Proteínas Virais/metabolismo , Motivos de Aminoácidos , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/antagonistas & inibidores , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Marchantia/genética , Metilação , Metiltransferases/antagonistas & inibidores , Metiltransferases/química , Metiltransferases/genética , Filogenia , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Potyvirus/genética , Ligação Proteica , Domínios Proteicos , Proteínas Recombinantes/metabolismo , Especificidade por Substrato
5.
PLoS One ; 16(9): e0255470, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34499670

RESUMO

TBR225 is one of the most popular commercial rice varieties in Northern Vietnam. However, this variety is highly susceptible to bacterial leaf blight (BLB), a disease caused by Xanthomonas oryzae pv. oryzae (Xoo) which can lead to important yield losses. OsSWEET14 belongs to the SWEET gene family that encodes sugar transporters. Together with other Clade III members, it behaves as a susceptibility (S) gene whose induction by Asian Xoo Transcription-Activator-Like Effectors (TALEs) is absolutely necessary for disease. In this study, we sought to introduce BLB resistance in the TBR225 elite variety. First, two Vietnamese Xoo strains were shown to up-regulate OsSWEET14 upon TBR225 infection. To investigate if this induction is connected with disease susceptibility, nine TBR225 mutant lines with mutations in the AvrXa7, PthXo3 or TalF TALEs DNA target sequences of the OsSWEET14 promoter were obtained using the CRISPR/Cas9 editing system. Genotyping analysis of T0 and T1 individuals showed that mutations were stably inherited. None of the examined agronomic traits of three transgene-free T2 edited lines were significantly different from those of wild-type TBR225. Importantly, one of these T2 lines, harboring the largest homozygous 6-bp deletion, displayed decreased OsSWEET14 expression as well as a significantly reduced susceptibility to a Vietnamese Xoo strains and complete resistance to another one. Our findings indicate that CRISPR/Cas9 editing conferred an improved BLB resistance to a Vietnamese commercial elite rice variety.


Assuntos
Resistência à Doença/imunologia , Regulação da Expressão Gênica de Plantas , Oryza/imunologia , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas , Xanthomonas/fisiologia , Sistemas CRISPR-Cas , Resistência à Doença/genética , Suscetibilidade a Doenças , Proteínas de Transporte de Monossacarídeos/antagonistas & inibidores , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Mutação , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética
6.
Int J Mol Sci ; 22(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34360584

RESUMO

Trichostatin A (TSA) is a representative histone deacetylase (HDAC) inhibitor that modulates epigenetic gene expression by regulation of chromatin remodeling in cells. To investigate whether the regulation of chromatin de-condensation by TSA can affect the increase in the efficiency of Cas9 protein-gRNA ribonucleoprotein (RNP) indel formation from plant cells, genome editing efficiency using lettuce and tobacco protoplasts was examined after several concentrations of TSA treatments (0, 0.1, 1 and 10 µM). RNP delivery from protoplasts was conducted by conventional polyethylene glycol (PEG) transfection protocols. Interestingly, the indel frequency of the SOC1 gene from TSA treatments was about 3.3 to 3.8 times higher than DMSO treatment in lettuce protoplasts. The TSA-mediated increase of indel frequency of the SOC1 gene in lettuce protoplasts occurred in a concentration-dependent manner, although there was not much difference. Similar to lettuce, TSA also increased the indel frequency by 1.5 to 1.8 times in a concentration-dependent manner during PDS genome editing using tobacco protoplasts. The MNase test clearly showed that chromatin accessibility with TSA treatments was higher than that of DMSO treatment. Additionally, TSA treatment significantly increased the level of histone H3 and H4 acetylation from lettuce protoplasts. The qRT-PCR analysis showed that expression of cell division-related genes (LsCYCD1-1, LsCYCD3-2, LsCYCD6-1, and LsCYCU4-1) was increased by TSA treatment. These findings could contribute to increasing the efficiency of CRISPR/Cas9-mediated genome editing. Furthermore, this could be applied for the development of useful genome-edited crops using the CRISPR/Cas9 system with plant protoplasts.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes/métodos , Ácidos Hidroxâmicos/farmacologia , /metabolismo , Proteínas de Plantas/metabolismo , Protoplastos/metabolismo , Divisão Celular , Genoma de Planta , /genética , Células Vegetais , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Inibidores da Síntese de Proteínas/farmacologia , Protoplastos/efeitos dos fármacos , /genética , /crescimento & desenvolvimento
7.
Sci Rep ; 11(1): 14748, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34285303

RESUMO

Candidemia caused by Candida spp. is a serious threat in hospital settings being a major cause of acquired infection and death and a possible contributor to Covid-19 mortality. Candidemia incidence has been rising worldwide following increases in fungicide-resistant pathogens highlighting the need for more effective antifungal agents with novel modes of action. The membrane-bound enzyme alternative oxidase (AOX) promotes fungicide resistance and is absent in humans making it a desirable therapeutic target. However, the lipophilic nature of the AOX substrate (ubiquinol-10) has hindered its kinetic characterisation in physiologically-relevant conditions. Here, we present the purification and expression of recombinant AOXs from C. albicans and C. auris in a self-assembled proteoliposome (PL) system. Kinetic parameters (Km and Vmax) with respect to ubiquinol-10 have been determined. The PL system has also been employed in dose-response assays with novel AOX inhibitors. Such information is critical for the future development of novel treatments for Candidemia.


Assuntos
Candida albicans/enzimologia , Farmacorresistência Fúngica , Proteínas Fúngicas/metabolismo , Lipossomos/metabolismo , Proteínas Mitocondriais/metabolismo , Oxirredutases/metabolismo , Proteínas de Plantas/metabolismo , Antifúngicos/farmacologia , Inibidores Enzimáticos/farmacologia , Proteínas Fúngicas/antagonistas & inibidores , Proteínas Fúngicas/genética , Cinética , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/genética , Oxirredutases/antagonistas & inibidores , Oxirredutases/genética , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
8.
EMBO J ; 40(15): e106800, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34156108

RESUMO

How organisms integrate metabolism with the external environment is a central question in biology. Here, we describe a novel regulatory small molecule, a proteogenic dipeptide Tyr-Asp, which improves plant tolerance to oxidative stress by directly interfering with glucose metabolism. Specifically, Tyr-Asp inhibits the activity of a key glycolytic enzyme, glyceraldehyde 3-phosphate dehydrogenase (GAPC), and redirects glucose toward pentose phosphate pathway (PPP) and NADPH production. In line with the metabolic data, Tyr-Asp supplementation improved the growth performance of both Arabidopsis and tobacco seedlings subjected to oxidative stress conditions. Moreover, inhibition of Arabidopsis phosphoenolpyruvate carboxykinase (PEPCK) activity by a group of branched-chain amino acid-containing dipeptides, but not by Tyr-Asp, points to a multisite regulation of glycolytic/gluconeogenic pathway by dipeptides. In summary, our results open the intriguing possibility that proteogenic dipeptides act as evolutionarily conserved small-molecule regulators at the nexus of stress, protein degradation, and metabolism.


Assuntos
Arabidopsis/efeitos dos fármacos , Dipeptídeos/farmacologia , Gliceraldeído-3-Fosfato Desidrogenases/antagonistas & inibidores , Proteínas de Plantas/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Simulação por Computador , Dipeptídeos/química , Dipeptídeos/metabolismo , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/química , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/metabolismo , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , NADP/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Via de Pentose Fosfato/efeitos dos fármacos , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Proteínas de Plantas/antagonistas & inibidores , Plântula/efeitos dos fármacos , Plântula/metabolismo , /metabolismo
9.
Biomolecules ; 11(5)2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-33946959

RESUMO

We examined the effects of two histone acetyltransferase (HAT) inhibitors on the activity of rice serotonin N-acetyltransferases (SNAT). Two rice recombinant SNAT isoenzymes (SNAT1 and SNAT2) were incubated in the presence of either MG149 or MB3, HAT inhibitors. MG149 significantly inhibited the SNAT enzymes in a dose-dependent manner, especially SNAT1, while SNAT2 was moderately inhibited. By contrast, MB3 had no effect on SNAT1 or SNAT2. The application of 100 µM MG149 to rice seedlings decreased melatonin by 1.6-fold compared to the control, whereas MB3 treatment did not alter the melatonin level. MG149 significantly decreased both melatonin and N-acetylserotonin when rice seedlings were challenged with cadmium, a potent elicitor of melatonin synthesis in rice. Although MG149 inhibited melatonin synthesis in rice seedlings, no melatonin deficiency-induced lamina angle decrease was observed due to the insufficient suppression of SNAT2, which is responsible for the lamina angle decrease in rice.


Assuntos
Arilalquilamina N-Acetiltransferase/genética , Melatonina/metabolismo , Oryza/metabolismo , Salicilatos/farmacologia , Arilalquilamina N-Acetiltransferase/antagonistas & inibidores , Cádmio/farmacologia , Relação Dose-Resposta a Droga , Oryza/genética , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Proteínas Recombinantes/metabolismo , Plântula/genética , Plântula/metabolismo , Serotonina/análogos & derivados , Serotonina/metabolismo
10.
ACS Chem Biol ; 16(10): 1968-1984, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33988963

RESUMO

Small molecule irreversible inhibitors are valuable tools for determining catalytically important active-site residues and revealing key details of the specificity, structure, and function of glycoside hydrolases (GHs). ß-glucans that contain backbone ß(1,3) linkages are widespread in nature, e.g., mixed-linkage ß(1,3)/ß(1,4)-glucans in the cell walls of higher plants and ß(1,3)glucans in yeasts and algae. Commensurate with this ubiquity, a large diversity of mixed-linkage endoglucanases (MLGases, EC 3.2.1.73) and endo-ß(1,3)-glucanases (laminarinases, EC 3.2.1.39 and EC 3.2.1.6) have evolved to specifically hydrolyze these polysaccharides, respectively, in environmental niches including the human gut. To facilitate biochemical and structural analysis of these GHs, with a focus on MLGases, we present here the facile chemo-enzymatic synthesis of a library of active-site-directed enzyme inhibitors based on mixed-linkage oligosaccharide scaffolds and N-bromoacetylglycosylamine or 2-fluoro-2-deoxyglycoside warheads. The effectiveness and irreversibility of these inhibitors were tested with exemplar MLGases and an endo-ß(1,3)-glucanase. Notably, determination of inhibitor-bound crystal structures of a human-gut microbial MLGase from Glycoside Hydrolase Family 16 revealed the orthogonal labeling of the nucleophile and catalytic acid/base residues with homologous 2-fluoro-2-deoxyglycoside and N-bromoacetylglycosylamine inhibitors, respectively. We anticipate that the selectivity of these inhibitors will continue to enable the structural and mechanistic analyses of ß-glucanases from diverse sources and protein families.


Assuntos
Celulases/antagonistas & inibidores , Inibidores Enzimáticos/química , Oligossacarídeos/química , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/química , Bacteroides/enzimologia , Domínio Catalítico/efeitos dos fármacos , Celulases/química , Cristalografia por Raios X , Ensaios Enzimáticos , Inibidores Enzimáticos/síntese química , Cinética , Oligossacarídeos/síntese química , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/química , Vitis/enzimologia
12.
Eur J Med Chem ; 220: 113470, 2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-33940464

RESUMO

We have recently reported on the development and trypanocidal activity of a class of inhibitors of Trypanosome Alternative Oxidase (TAO) that are targeted to the mitochondrial matrix by coupling to lipophilic cations via C14 linkers to enable optimal interaction with the enzyme's active site. This strategy resulted in a much-enhanced anti-parasite effect, which we ascribed to the greater accumulation of the compound at the location of the target protein, i.e. the mitochondrion, but to date this localization has not been formally established. We therefore synthesized a series of fluorescent analogues to visualize accumulation and distribution within the cell. The fluorophore chosen, julolidine, has the remarkable extra feature of being able to function as a viscosity sensor and might thus additionally act as a probe of the cellular glycerol that is expected to be produced when TAO is inhibited. Two series of fluorescent inhibitor conjugates incorporating a cationic julolidine-based viscosity sensor were synthesized and their photophysical and biological properties were studied. These probes display a red emission, with a high signal-to-noise ratio (SNR), using both single- and two-photon excitation. Upon incubation with T. brucei and mammalian cells, the fluorescent inhibitors 1a and 2a were taken up selectively in the mitochondria as shown by live-cell imaging. Efficient partition of 1a in functional isolated (rat liver) mitochondria was estimated to 66 ± 20% of the total. The compounds inhibited recombinant TAO enzyme in the submicromolar (1a, 2c, 2d) to low nanomolar range (2a) and were effective against WT and multidrug-resistant trypanosome strains (B48, AQP1-3 KO) in the submicromolar range. Good selectivity (SI > 29) over mammalian HEK cells was observed. However, no viscosity-related shift could be detected, presumably because the glycerol was produced cytosolically, and released through aquaglyceroporins, whereas the probe was located, virtually exclusively, in the trypanosome's mitochondrion.


Assuntos
Inibidores Enzimáticos/farmacologia , Corantes Fluorescentes/farmacologia , Proteínas Mitocondriais/antagonistas & inibidores , Oxirredutases/antagonistas & inibidores , Proteínas de Plantas/antagonistas & inibidores , Trypanosoma brucei brucei/efeitos dos fármacos , Trypanosoma/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Teoria da Densidade Funcional , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Células HEK293 , Humanos , Microscopia de Fluorescência , Proteínas Mitocondriais/metabolismo , Estrutura Molecular , Imagem Óptica , Oxirredutases/metabolismo , Proteínas de Plantas/metabolismo , Relação Estrutura-Atividade , Trypanosoma/enzimologia , Trypanosoma brucei brucei/enzimologia
13.
Int J Mol Sci ; 22(6)2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33807069

RESUMO

Studies implicating an important role for apyrase (NTPDase) enzymes in plant growth and development began appearing in the literature more than three decades ago. After early studies primarily in potato, Arabidopsis and legumes, especially important discoveries that advanced an understanding of the biochemistry, structure and function of these enzymes have been published in the last half-dozen years, revealing that they carry out key functions in diverse other plants. These recent discoveries about plant apyrases include, among others, novel findings on its crystal structures, its biochemistry, its roles in plant stress responses and its induction of major changes in gene expression when its expression is suppressed or enhanced. This review will describe and discuss these recent advances and the major questions about plant apyrases that remain unanswered.


Assuntos
Apirase/química , Apirase/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Apirase/antagonistas & inibidores , Apirase/genética , Domínio Catalítico , Fenômenos Químicos , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica de Plantas , Modelos Moleculares , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Conformação Proteica , Relação Estrutura-Atividade
14.
Food Chem ; 353: 129519, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33740507

RESUMO

Recently, the interest in the plant proteases has greatly increased. However, only a few of proteases are isolated from the hugely produced oilseeds for the practical utilizations. In this study, the raw sesame milk prepared from peeled sesame seeds was separated into floating, skim, and precipitate fractions by centrifugation. The predominant aspartic endopeptidases and serine carboxypeptidases, which exerted high synergetic activity at pH 4.5-5 and 50-60 °C, were identified in the skim by the liquid chromatography tandem mass spectrometry, Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis, protease inhibitor assay, trichloroacetic acid-nitrogen soluble index (TCA-NSI), and free amino acid analyses. By incubating the mixture (protein content, 2%) of skim and precipitate at pH 4.5 and 50 °C for 6 h, the TCA-NSI and free amino acids achieved to 38.42% and 3148 mg/L, respectively. Moreover, these proteases efficiently degraded the proteins from soybean, peanut, and bovine milk.


Assuntos
Ácido Aspártico Endopeptidases/metabolismo , Carboxipeptidases/metabolismo , Proteínas de Plantas/metabolismo , Sesamum/metabolismo , Ácido Aspártico Endopeptidases/análise , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Carboxipeptidases/análise , Carboxipeptidases/antagonistas & inibidores , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Proteínas de Plantas/análise , Proteínas de Plantas/antagonistas & inibidores , Inibidores de Proteases/química , Sementes/metabolismo , Proteínas de Soja/análise , Proteínas de Soja/metabolismo , Espectrometria de Massas em Tandem , Temperatura , Água/química
15.
J Agric Food Chem ; 69(4): 1197-1205, 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33470815

RESUMO

The occurrence of multiple herbicide resistant weeds has increased considerably in glyphosate-resistant soybean fields in Brazil; however, the mechanisms governing this resistance have not been studied. In its study, the target-site and nontarget-site mechanisms were characterized in an Eleusine indica population (R-15) with multiple resistance to the acetyl-CoA carboxylase (ACCase) inhibitors, glyphosate, imazamox, and paraquat. Absorption and translocation rates of 14C-diclofop-methyl14C-imazamox and 14C-glyphosate of the R-15 population were similar to those of a susceptible (S-15) population; however, the R-15 population translocated ∼38% less 14C-paraquat to the rest of plant and roots than the S-15 population. Furthermore, the R-15 plants metabolized (by P450 cytochrome) 55% and 88% more diclofop-methyl (conjugate) and imazamox (imazamox-OH and conjugate), respectively, than the S-15 plants. In addition, the Pro-106-Ser mutation was found in the EPSPS gene of this population. This report describes the first characterization of the resistance mechanisms in a multiple herbicide resistant weed from Brazil.


Assuntos
Eleusine/efeitos dos fármacos , Glicina/análogos & derivados , Resistência a Herbicidas , Herbicidas/farmacologia , Acetil-CoA Carboxilase/antagonistas & inibidores , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Brasil , Eleusine/enzimologia , Eleusine/genética , Inibidores Enzimáticos/farmacologia , Glicina/farmacologia , Imidazóis/farmacologia , Paraquat/farmacologia , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
16.
Int J Biol Macromol ; 172: 263-269, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33453254

RESUMO

In insects, the cytochrome P450 CYP6B family plays key roles in the detoxification of toxic plant substances. However, the function of CYP6 family genes in degrading plant toxicants in Tribolium castaneum, an extremely destructive global storage pest, have yet to be elucidated. In this study, a T. castaneum CYP gene, TcCYP6BQ7, was characterized. TcCYP6BQ7 expression was significantly induced after exposure to essential oil of the plant Artemisia vulgaris (EOAV). Spatiotemporal expression profiling revealed that TcCYP6BQ7 expression was higher in larval and adult stages of T. castaneum than in other developmental stages, and that TcCYP6BQ7 was predominantly expressed in the brain and hemolymph from the late larval stage. TcCYP6BQ7 silencing by RNA interference increased larvae mortality in response to EOAV from 49.67% to 71.67%, suggesting that this gene is associated with plant toxicant detoxification. Combined results from this study indicate that the CYP6 family gene TcCYP6BQ7 likely plays a pivotal role in influencing the susceptibility of T. castaneum to plant toxicants. These findings may have implications for the development of novel therapeutics to control this agriculturally important pest.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Óleos Voláteis/farmacologia , Proteínas de Plantas/genética , Pupa/efeitos dos fármacos , Tribolium/efeitos dos fármacos , Animais , Artemisia/química , Artemisia/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Feminino , Regulação da Expressão Gênica , Hemolinfa/efeitos dos fármacos , Hemolinfa/metabolismo , Inseticidas/isolamento & purificação , Inseticidas/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Longevidade/efeitos dos fármacos , Longevidade/genética , Masculino , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/metabolismo , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/metabolismo , Pupa/genética , Pupa/crescimento & desenvolvimento , Pupa/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Tribolium/genética , Tribolium/crescimento & desenvolvimento , Tribolium/metabolismo
17.
Food Chem ; 338: 127928, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32919374

RESUMO

We investigated the inhibitory effect and binding mechanism of four selected compounds (ascorbic acid, l-cysteine, glutathione, and citric acid) on membrane-bound polyphenol oxidases (mPPO) using spectroscopic and molecular docking techniques. Kinetic analysis demonstrated that these inhibitors reversibly inhibited the mPPO activity. Fluorescence spectroscopy revealed that the intrinsic fluorescence intensity of mPPO was quenched by inhibitors with a single class of the inhibition site on mPPO. Amino acid residues His 180, His 201, His 366, Cys 184, Glu 328, and Asn 333 were the important binding sites in the active center. These sites were identified using molecular docking techniques. Our findings suggested that the inhibitors were allosterically bound to the active center of mPPO through hydrogen bonds and ion contacts. This study provides new insights into the active site residues responsible for catalyzing mPPO and provides applicable information about the design of mPPO inhibitors.


Assuntos
Catecol Oxidase/metabolismo , Malus/enzimologia , Simulação de Acoplamento Molecular , Proteínas de Plantas/metabolismo , Regulação Alostérica , Ácido Ascórbico/química , Ácido Ascórbico/metabolismo , Sítios de Ligação , Catecol Oxidase/antagonistas & inibidores , Cisteína/química , Cisteína/metabolismo , Glutationa/química , Glutationa/metabolismo , Cinética , Proteínas de Plantas/antagonistas & inibidores , Espectrometria de Fluorescência
18.
Sci China Life Sci ; 64(10): 1624-1633, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33165814

RESUMO

Herbicide-tolerant rice varieties generated by genome editing are highly desirable for weed control. We have used a cytosine base editor to create a series of missense mutations in the P171 and/or G628 codons of the acetolactate synthase (ALS) gene to confer herbicide tolerance in rice. The four different missense mutations in the P171 codon, P171S, P171A, P171Y and P171F, exhibited different patterns of tolerance towards five representative herbicides from five chemical families of ALS inhibitors. For example, P171S and P171A had lower levels of tolerance than P171Y and P171F to bispyribac but not to the other herbicides. Interestingly, a novel triple mutant (P171F/G628E/G629S) had the highest tolerance to all five tested herbicides. Field trials showed that both P171F and P171F/G628E/G629S could potentially be used with nicosulfuron. Our work illustrates an effective way of using base editing to generate herbicide tolerance in elite rice varieties.


Assuntos
Acetolactato Sintase/antagonistas & inibidores , Tolerância a Medicamentos/genética , Edição de Genes , Herbicidas/farmacologia , Oryza/genética , Acetolactato Sintase/genética , Citosina , Inibidores Enzimáticos/farmacologia , Mutação , Oryza/efeitos dos fármacos , Oryza/enzimologia , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas
19.
FEBS Lett ; 595(3): 379-388, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33263189

RESUMO

The tobacco variant Nicotiana benthamiana has recently emerged as a versatile host for the manufacturing of protein therapeutics, but the fidelity of many recombinant proteins generated in this system is compromised by inadvertent proteolysis. Previous studies have revealed that the anti-HIV-1 antibodies 2F5 and PG9 as well as the protease inhibitor α1 -antitrypsin (A1AT) are particularly susceptible to N. benthamiana proteases. Here, we identify two subtilisin-like serine proteases (NbSBT1 and NbSBT2) whose combined action is sufficient to account for all major cleavage events observed upon expression of 2F5, PG9 and A1AT in N. benthamiana. We propose that downregulation of NbSBT1 and NbSBT2 activities could constitute a powerful means to optimize the performance of this promising platform for the production of biopharmaceuticals. DATABASES: NbSBT sequence data are available in the DDBJ/EMBL/GenBank databases under the accession numbers MN534996 to MN535005.


Assuntos
Anticorpos Monoclonais/química , Anticorpos Anti-HIV/química , Proteínas de Plantas/antagonistas & inibidores , Subtilisinas/antagonistas & inibidores , alfa 1-Antitripsina/química , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/metabolismo , Clorometilcetonas de Aminoácidos/farmacologia , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/genética , Expressão Gênica , Anticorpos Anti-HIV/biossíntese , Anticorpos Anti-HIV/genética , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Fluoreto de Fenilmetilsulfonil/farmacologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Inibidores de Proteases/farmacologia , Proteólise , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Subtilisinas/genética , Subtilisinas/metabolismo , /enzimologia , alfa 1-Antitripsina/biossíntese , alfa 1-Antitripsina/genética
20.
Methods Mol Biol ; 2264: 163-175, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33263909

RESUMO

RNA interference (RNAi) is a posttranscriptional gene silencing phenomenon induced by double-stranded RNA. It has been widely used as a knockdown technology to analyze gene function in many organisms. In tomato, RNAi technology has widely been used as a reverse genetic tool for functional genomics study. Generally, RNAi is often achieved through transgenes producing hairpin RNA molecules. RNAi lines have the advantage with respect to more modern CRISPR/Cas9 mutants of different levels of downregulation of target gene, and allow the characterization of life-essential genes that cannot be knocked out without killing the organism. Also, RNAi allows to suppress gene expression in multigene families in a regulated manner. In this chapter, an efficient approach to create RNAi stable knockdown-transformed tomato lines is reported. In order, it describes the choice of the target silencing fragment, a highly efficient cloning strategy for the hairpin RNA construct production, a relatively easy procedure to transform and regenerate tomato plants using Agrobacterium tumefaciens and a methodology to test the goodness of the transformation procedure.


Assuntos
Agrobacterium tumefaciens/genética , Inativação Gênica , Proteínas de Plantas/antagonistas & inibidores , Plantas Geneticamente Modificadas/genética , Interferência de RNA , Solanum lycopersicum/genética , Transformação Genética , Solanum lycopersicum/crescimento & desenvolvimento , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , RNA de Cadeia Dupla , Transgenes
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