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1.
Mol Plant Microbe Interact ; 37(4): 380-395, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38114195

RESUMO

Bemisia tabaci (whitefly) is a polyphagous agroeconomic pest species complex. Two members of this species complex, Mediterranean (MED) and Middle-East-Asia Minor 1 (MEAM1), have a worldwide distribution and have been shown to manipulate plant defenses through effectors. In this study, we used three different strategies to identify three MEAM1 proteins that can act as effectors. Effector B1 was identified using a bioinformatics-driven effector-mining strategy, whereas effectors S1 and P1 were identified in the saliva of whiteflies collected from artificial diet and in phloem exudate of tomato on which nymphs were feeding, respectively. These three effectors were B. tabaci specific and able to increase whitefly fecundity when transiently expressed in tobacco plants (Nicotiana tabacum). Moreover, they reduced growth of Pseudomonas syringae pv. tabaci in Nicotiana benthamiana. All three effectors changed gene expression in planta, and B1 and S1 also changed phytohormone levels. Gene ontology and KEGG pathway enrichment analysis pinpointed plant-pathogen interaction and photosynthesis as the main enriched pathways for all three effectors. Our data thus show the discovery and validation of three new B. tabaci MEAM1 effectors that increase whitefly fecundity and modulate plant immunity. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Hemípteros , Nicotiana , Animais , Nicotiana/genética , Nicotiana/microbiologia , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Solanum lycopersicum/genética , Solanum lycopersicum/microbiologia , Solanum lycopersicum/parasitologia , Pseudomonas syringae/fisiologia , Doenças das Plantas/parasitologia , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Plantas/metabolismo , Fertilidade/genética
2.
Plant Biotechnol J ; 22(1): 248-261, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37822043

RESUMO

Vascular wilt diseases caused by Fusarium oxysporum are a major threat to many agriculturally important crops. Genetic resistance is rare and inevitably overcome by the emergence of new races. To identify potentially durable and non-race-specific genetic resistance against Fusarium wilt diseases, we set out to identify effector targets in tomato that mediate susceptibility to the fungus. For this purpose, we used the SIX8 effector protein, an important and conserved virulence factor present in many pathogenic F. oxysporum isolates. Using protein pull-downs and yeast two-hybrid assays, SIX8 was found to interact specifically with two members of the tomato TOPLESS family: TPL1 and TPL2. Loss-of-function mutations in TPL1 strongly reduced disease susceptibility to Fusarium wilt and a tpl1;tpl2 double mutant exerted an even higher level of resistance. Similarly, Arabidopsis tpl;tpr1 mutants became significantly less diseased upon F. oxysporum inoculation as compared to wildtype plants. We conclude that TPLs encode susceptibility genes whose mutation can confer resistance to F. oxysporum.


Assuntos
Arabidopsis , Fusarium , Solanum lycopersicum , Arabidopsis/genética , Arabidopsis/microbiologia , Solanum lycopersicum/genética , Fatores de Virulência/genética , Mutação/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia
3.
Plant Physiol ; 182(1): 361-377, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31570508

RESUMO

SNF1-RELATED PROTEIN KINASES 2 (SnRK2) are important components of early osmotic and salt stress signaling pathways in plants. The Arabidopsis (Arabidopsis thaliana) SnRK2 family comprises the abscisic acid (ABA)-activated protein kinases SnRK2.2, SnRK2.3, SnRK2.6, SnRK2.7, and SnRK2.8, and the ABA-independent subclass 1 protein kinases SnRK2.1, SnRK2.4, SnRK2.5, SnRK2.9, and SnRK2.10. ABA-independent SnRK2s act at the posttranscriptional level via phosphorylation of VARICOSE (VCS), a member of the mRNA decapping complex, that catalyzes the first step of 5'mRNA decay. Here, we identified VCS and VARICOSE RELATED (VCR) as interactors and phosphorylation targets of SnRK2.5, SnRK2.6, and SnRK2.10. All three protein kinases phosphorylated Ser-645 and Ser-1156 of VCS, whereas SnRK2.6 and SnRK2.10 also phosphorylated VCS Ser-692 and Ser-680 of VCR. We showed that subclass 1 SnRK2s, VCS, and 5' EXORIBONUCLEASE 4 (XRN4) are involved in regulating root growth under control conditions as well as modulating root system architecture in response to salt stress. Our results suggest interesting patterns of redundancy within subclass 1 SnRK2 protein kinases, with SnRK2.1, SnRK2.5, and SnRK2.9 controlling root growth under nonstress conditions and SnRK2.4 and SnRK2.10 acting mostly in response to salinity. We propose that subclass 1 SnRK2s function in root development under salt stress by affecting the transcript levels of aquaporins, as well as CYP79B2, an enzyme involved in auxin biosynthesis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , RNA Mensageiro/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Exorribonucleases/genética , Exorribonucleases/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , RNA Mensageiro/genética , Sais/farmacologia , Transdução de Sinais/efeitos dos fármacos
4.
Int J Mol Sci ; 22(17)2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34502250

RESUMO

Bacillus subtilis vegetative cells switch to sporulation upon nutrient limitation. To investigate the proteome dynamics during sporulation, high-resolution time-lapse proteomics was performed in a cell population that was induced to sporulate synchronously. Here, we are the first to comprehensively investigate the changeover of sporulation regulatory proteins, coat proteins, and other proteins involved in sporulation and spore biogenesis. Protein co-expression analysis revealed four co-expressed modules (termed blue, brown, green, and yellow). Modules brown and green are upregulated during sporulation and contain proteins associated with sporulation. Module blue is negatively correlated with modules brown and green, containing ribosomal and metabolic proteins. Finally, module yellow shows co-expression with the three other modules. Notably, several proteins not belonging to any of the known transcription regulons were identified as co-expressed with modules brown and green, and might also play roles during sporulation. Finally, levels of some coat proteins, for example morphogenetic coat proteins, decreased late in sporulation.


Assuntos
Bacillus subtilis/metabolismo , Bacillus subtilis/fisiologia , Proteoma/análise , Proteoma/metabolismo , Esporos Bacterianos/metabolismo , Esporos Bacterianos/fisiologia , Bacillus subtilis/citologia , Proteínas de Bactérias/classificação , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Esporos Bacterianos/citologia , Fatores de Transcrição/metabolismo , Fatores de Transcrição/fisiologia
5.
Int J Mol Sci ; 22(22)2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34830357

RESUMO

Membrane proteins are fascinating since they play an important role in diverse cellular functions and constitute many drug targets. Membrane proteins are challenging to analyze. The spore, the most resistant form of known life, harbors a compressed inner membrane. This membrane acts not only as a barrier for undesired molecules but also as a scaffold for proteins involved in signal transduction and the transport of metabolites during spore germination and subsequent vegetative growth. In this study, we adapted a membrane enrichment method to study the membrane proteome of spores and cells of the food-borne pathogen Bacillus cereus using quantitative proteomics. Using bioinformatics filtering we identify and quantify 498 vegetative cell membrane proteins and 244 spore inner membrane proteins. Comparison of vegetative and spore membrane proteins showed there were 54 spore membrane-specific and 308 cell membrane-specific proteins. Functional characterization of these proteins showed that the cell membrane proteome has a far larger number of transporters, receptors and proteins related to cell division and motility. This was also reflected in the much higher expression level of many of these proteins in the cellular membrane for those proteins that were in common with the spore inner membrane. The spore inner membrane had specific expression of several germinant receptors and spore-specific proteins, but also seemed to show a preference towards the use of simple carbohydrates like glucose and fructose owing to only expressing transporters for these. These results show the differences in membrane proteome composition and show us the specific proteins necessary in the inner membrane of a dormant spore of this toxigenic spore-forming bacterium to survive adverse conditions.


Assuntos
Bacillus cereus/genética , Proteínas de Bactérias/genética , Doenças Transmitidas por Alimentos/genética , Proteoma/genética , Bacillus cereus/patogenicidade , Proteínas de Bactérias/classificação , Membrana Celular/genética , Contaminação de Alimentos , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Humanos , Proteínas de Membrana/classificação , Proteínas de Membrana/genética , Proteômica , Esporos Bacterianos/genética , Esporos Bacterianos/crescimento & desenvolvimento , Esporos Bacterianos/patogenicidade
6.
J Proteome Res ; 15(2): 585-94, 2016 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-26731423

RESUMO

The endospore is the dormant form of Bacillus subtilis and many other Firmicutes. By sporulation, these spore formers can survive very harsh physical and chemical conditions. Yet, they need to go through germination to return to their growing form. The spore inner membrane (IM) has been shown to play an essential role in triggering the initiation of germination. In this study, we isolated the IM of bacterial spores, in parallel with the isolation of the membrane of vegetative cells. With the use of GeLC-MS/MS, over 900 proteins were identified from the B. subtilis spore IM preparations. By bioinformatics-based membrane protein predictions, ca. one-third could be predicted to be membrane-localized. A large number of unique proteins as well as proteins common to the two membrane proteomes were identified. In addition to previously known IM proteins, a number of IM proteins were newly identified, at least some of which are likely to provide new insights into IM physiology, unveiling proteins putatively involved in spore germination machinery and hence putative germination inhibition targets.


Assuntos
Bacillus subtilis/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Membrana/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Esporos Bacterianos/metabolismo , Proteínas de Bactérias/classificação , Cromatografia Líquida , Eletroforese em Gel de Poliacrilamida , Proteínas de Membrana/classificação , Microscopia Eletrônica de Transmissão , Proteoma/classificação , Esporos Bacterianos/ultraestrutura , Espectrometria de Massas em Tandem
7.
Biochim Biophys Acta ; 1854(10 Pt A): 1269-79, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26049081

RESUMO

Time-series transcript- and protein-profiles were measured upon initiation of carbon catabolite repression in Escherichia coli, in order to investigate the extent of post-transcriptional control in this prototypical response. A glucose-limited chemostat culture was used as the CCR-free reference condition. Stopping the pump and simultaneously adding a pulse of glucose, that saturated the cells for at least 1h, was used to initiate the glucose response. Samples were collected and subjected to quantitative time-series analysis of both the transcriptome (using microarray analysis) and the proteome (through a combination of 15N-metabolic labeling and mass spectrometry). Changes in the transcriptome and corresponding proteome were analyzed using statistical procedures designed specifically for time-series data. By comparison of the two sets of data, a total of 96 genes were identified that are post-transcriptionally regulated. This gene list provides candidates for future in-depth investigation of the molecular mechanisms involved in post-transcriptional regulation during carbon catabolite repression in E. coli, like the involvement of small RNAs.


Assuntos
Proteínas de Escherichia coli/genética , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Glucose/deficiência , Proteoma , Transcriptoma , Reatores Biológicos , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Perfilação da Expressão Gênica , Marcação por Isótopo , Análise em Microsséries , Anotação de Sequência Molecular , Isótopos de Nitrogênio , Fatores de Tempo
8.
Metab Eng ; 35: 83-94, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26869136

RESUMO

Retinal-based photosynthesis may contribute to the free energy conversion needed for growth of an organism carrying out oxygenic photosynthesis, like a cyanobacterium. After optimization, this may even enhance the overall efficiency of phototrophic growth of such organisms in sustainability applications. As a first step towards this, we here report on functional expression of the archetype proteorhodopsin in Synechocystis sp. PCC 6803. Upon use of the moderate-strength psbA2 promoter, holo-proteorhodopsin is expressed in this cyanobacterium, at a level of up to 10(5) molecules per cell, presumably in a hexameric quaternary structure, and with approximately equal distribution (on a protein-content basis) over the thylakoid and the cytoplasmic membrane fraction. These results also demonstrate that Synechocystis sp. PCC 6803 has the capacity to synthesize all-trans-retinal. Expressing a substantial amount of a heterologous opsin membrane protein causes a substantial growth retardation Synechocystis, as is clear from a strain expressing PROPS, a non-pumping mutant derivative of proteorhodopsin. Relative to this latter strain, proteorhodopsin expression, however, measurably stimulates its growth.


Assuntos
Expressão Gênica , Rodopsinas Microbianas/biossíntese , Synechocystis/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Rodopsinas Microbianas/genética , Synechocystis/genética
9.
Int J Mol Sci ; 17(11)2016 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-27792189

RESUMO

The structural maintenance of chromosomes (SMC) protein complexes shape and regulate the structure and dynamics of chromatin, thereby controlling many chromosome-based processes such as cell cycle progression, differentiation, gene transcription and DNA repair. The SMC5/6 complex is previously described to promote DNA double-strand breaks (DSBs) repair by sister chromatid recombination, and found to be essential for resolving recombination intermediates during meiotic recombination. Moreover, in budding yeast, SMC5/6 provides structural organization and topological stress relief during replication in mitotically dividing cells. Despite the essential nature of the SMC5/6 complex, the versatile mechanisms by which SMC5/6 functions and its molecular regulation in mammalian cells remain poorly understood. By using a human osteosarcoma cell line (U2OS), we show that after the CRISPR-Cas9-mediated removal of the SMC5/6 subunit NSMCE2, treatment with the topoisomerase II inhibitor etoposide triggered an increased sensitivity in cells lacking NSMCE2. In contrast, NSMCE2 appeared not essential for a proper DNA damage response or cell survival after DSB induction by ionizing irradiation (IR). Interestingly, by way of immunoprecipitations (IPs) and mass spectrometry, we found that the SMC5/6 complex physically interacts with the DNA topoisomerase II α (TOP2A). We therefore propose that the SMC5/6 complex functions in resolving TOP2A-mediated DSB-repair intermediates generated during replication.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Ligases/metabolismo , Antígenos de Neoplasias/metabolismo , Sistemas CRISPR-Cas , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos da radiação , Proteínas Cromossômicas não Histona , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos da radiação , DNA Topoisomerases Tipo II/metabolismo , Proteínas de Ligação a DNA/metabolismo , Etoposídeo/efeitos adversos , Humanos , Ligases/genética , Proteínas de Ligação a Poli-ADP-Ribose , Mapas de Interação de Proteínas , Inibidores da Topoisomerase II/efeitos adversos
10.
J Proteome Res ; 14(5): 2169-76, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25853650

RESUMO

Bacillus weihenstephanensis is a subspecies of the Bacillus cereus sensu lato group of spore-forming bacteria known to cause food spoilage or food poisoning. The key distinguishing phenotype of B. weihenstephanensis is its ability to grow below 7 °C or, from a food safety perspective, to grow and potentially produce toxins in a refrigerated environment. Comparison of the proteome profile of B. weihenstephanensis upon its exposure to different culturing conditions can reveal clues to the mechanistic basis of its psychrotolerant phenotype as well as elucidate relevant aspects of its toxigenic profile. To this end, the genome of the type strain B. weihenstephanensis WSBC 10204 was sequenced and annotated. Subsequently, the proteome profiles of cells grown at either 6 or 30 °C were compared, which revealed considerable differences and indicated several hundred (uncharacterized) proteins as being subproteome- and/or temperature-specific. In this manner, several processes were newly indicated to be dependent on growth temperature, such as varying carbon flux routes and a different role for the urea cycle. Furthermore, a possible post-translational regulatory function for acetylation was suggested. Toxin production was determined to be largely independent of growth temperature.


Assuntos
Bacillus cereus/genética , Proteínas de Bactérias/genética , Genoma Bacteriano , Processamento de Proteína Pós-Traducional , Proteoma/genética , Acetilação , Bacillus cereus/metabolismo , Proteínas de Bactérias/metabolismo , Ciclo do Carbono/fisiologia , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Enterotoxinas , Microbiologia de Alimentos , Isoformas de Proteínas , Proteoma/metabolismo , Análise de Sequência de DNA , Temperatura , Ureia/metabolismo
11.
Anal Chem ; 87(10): 5387-94, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25894977

RESUMO

Stationary-phase-assisted modulation is used to overcome one of the limitations of contemporary comprehensive two-dimensional liquid chromatography, which arises from the combination of a first-dimension column that is typically narrow and long and a second-dimension column that is wide and short. Shallow gradients at low flow rates are applied in the first dimension, whereas fast analyses (at high flow rates) are required in the second dimension. Limitations of this approach include a low sample capacity of the first-dimension column and a high dilution of the sample in the complete system. Moreover, the relatively high flow rates used for the second dimension make direct (splitless) hyphenation to mass spectrometry difficult. In the present study we demonstrate that stationary-phase-assisted modulation can be implemented in an online comprehensive two-dimensional LC (LC × LC) setup to shift this paradigm. The proposed active modulation makes it possible to choose virtually any combination of first- and second-dimension column diameters without loss in system performance. In the current setup, a 0.30 mm internal diameter first-dimension column with a relatively high loadability is coupled to a 0.075 mm internal diameter second-dimension column. This actively modulated system is coupled to a nanoelectrospray high-resolution mass spectrometer and applied for the separation of the tryptic peptides of a six-protein mixture and for the proteome-wide analyses of yeast from Saccharomyces cerevisiae. In the latter application, about 20000 MS/MS spectra are generated within 24 h analysis time, resulting in the identification of 701 proteins.


Assuntos
Proteômica/métodos , Saccharomyces cerevisiae/metabolismo , Métodos Analíticos de Preparação de Amostras , Cromatografia Líquida , Sais/química , Espectrometria de Massas em Tandem
12.
FEMS Yeast Res ; 15(8)2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26546455

RESUMO

Attachment to human host tissues or abiotic medical devices is a key step in the development of infections by Candida glabrata. The genome of this pathogenic yeast codes for a large number of adhesins, but proteomic work using reference strains has shown incorporation of only few adhesins in the cell wall. By making inventories of the wall proteomes of hyperadhesive clinical isolates and reference strain CBS138 using mass spectrometry, we describe the cell wall proteome of C. glabrata and tested the hypothesis that hyperadhesive isolates display differential incorporation of adhesins. Two clinical strains (PEU382 and PEU427) were selected, which both were hyperadhesive to polystyrene and showed high surface hydrophobicity. Cell wall proteome analysis under biofilm-forming conditions identified a core proteome of about 20 proteins present in all C. glabrata strains. In addition, 12 adhesin-like wall proteins were identified in the hyperadherent strains, including six novel adhesins (Awp8-13) of which only Awp12 was also present in CBS138. We conclude that the hyperadhesive capacity of these two clinical C. glabrata isolates is correlated with increased and differential incorporation of cell wall adhesins. Future studies should elucidate the role of the identified proteins in the establishment of C. glabrata infections.


Assuntos
Candida glabrata/química , Parede Celular/química , Proteínas Fúngicas/análise , Proteoma/análise , Candida glabrata/isolamento & purificação , Candidíase/microbiologia , Humanos , Espectrometria de Massas , Proteômica
13.
Appl Environ Microbiol ; 80(7): 2229-39, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24487531

RESUMO

Hydrogen peroxide production is a well-known trait of many bacterial species associated with the human body. In the presence of oxygen, the probiotic lactic acid bacterium Lactobacillus johnsonii NCC 533 excretes up to 1 mM H(2)O(2), inducing growth stagnation and cell death. Disruption of genes commonly assumed to be involved in H(2)O(2) production (e.g., pyruvate oxidase, NADH oxidase, and lactate oxidase) did not affect this. Here we describe the purification of a novel NADH-dependent flavin reductase encoded by two highly similar genes (LJ_0548 and LJ_0549) that are conserved in lactobacilli belonging to the Lactobacillus acidophilus group. The genes are predicted to encode two 20-kDa proteins containing flavin mononucleotide (FMN) reductase conserved domains. Reductase activity requires FMN, flavin adenine dinucleotide (FAD), or riboflavin and is specific for NADH and not NADPH. The Km for FMN is 30 ± 8 µM, in accordance with its proposed in vivo role in H(2)O(2) production. Deletion of the encoding genes in L. johnsonii led to a 40-fold reduction of hydrogen peroxide formation. H(2)O(2) production in this mutant could only be restored by in trans complementation of both genes. Our work identifies a novel, conserved NADH-dependent flavin reductase that is prominently involved in H(2)O(2) production in L. johnsonii.


Assuntos
Coenzimas/metabolismo , FMN Redutase/metabolismo , Peróxido de Hidrogênio/metabolismo , Lactobacillus/metabolismo , NAD/metabolismo , FMN Redutase/química , FMN Redutase/isolamento & purificação , Deleção de Genes , Teste de Complementação Genética , Cinética , Peso Molecular
14.
Biochem J ; 450(3): 573-81, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23323832

RESUMO

PA (phosphatidic acid) is a lipid second messenger involved in an array of processes occurring during a plant's life cycle. These include development, metabolism, and both biotic and abiotic stress responses. PA levels increase in response to salt, but little is known about its function in the earliest responses to salt stress. In the present study we have combined an approach to isolate peripheral membrane proteins of Arabidopsis thaliana roots with lipid-affinity purification, to identify putative proteins that interact with PA and are recruited to the membrane in response to salt stress. Of the 42 putative PA-binding proteins identified by MS, a set of eight new candidate PA-binding proteins accumulated at the membrane fraction after 7 min of salt stress. Among these were CHC (clathrin heavy chain) isoforms, ANTH (AP180 N-terminal homology) domain clathrin-assembly proteins, a putative regulator of potassium transport, two ribosomal proteins, GAPDH (glyceraldehyde 3-phosphate dehydrogenase) and a PI (phosphatidylinositol) 4-kinase. PA binding and salt-induced membrane recruitment of GAPDH and CHC were confirmed by Western blot analysis of the cellular fractions. In conclusion, the approach of the present study is an effective way to isolate biologically relevant lipid-binding proteins and provides new leads in the study of PA-mediated salt-stress responses in roots.


Assuntos
Proteínas de Arabidopsis/isolamento & purificação , Proteínas de Arabidopsis/metabolismo , Arabidopsis/química , Ácidos Fosfatídicos/metabolismo , Raízes de Plantas/química , Tolerância ao Sal , Algoritmos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/fisiologia , Proteínas de Transporte/isolamento & purificação , Proteínas de Transporte/metabolismo , Proteínas de Transporte/fisiologia , Proteínas de Membrana/isolamento & purificação , Proteínas de Membrana/metabolismo , Modelos Biológicos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Ligação Proteica/efeitos dos fármacos , Proteoma/análise , Proteoma/efeitos dos fármacos , Proteoma/isolamento & purificação , Tolerância ao Sal/genética , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/fisiologia
15.
J Proteome Res ; 12(10): 4507-21, 2013 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-23998435

RESUMO

Bacillus cereus, responsible for food poisoning, and Clostridium difficile, the causative agent of Clostridium difficile-associated diarrhea (CDAD), are both spore-forming pathogens involved in food spoilage, food intoxication, and other infections in humans and animals. The proteinaceous coat and the exosporium layers from spores are important for their resistance and pathogenicity characteristics. The exosporium additionally provides an ability to adhere to surfaces eventually leading to spore survival in food. Thus, studying these layers and identifying suitable protein targets for rapid detection and removal of spores is of the utmost importance. In this study, we identified 100 proteins from B. cereus spore coat, exosporium and 54 proteins from the C. difficile coat insoluble protein fraction. In an attempt to define a universal set of spore outer layer proteins, we identified 11 superfamily domains common to the identified proteins from two Bacilli and one Clostridium species. The evaluated orthologue relationships of identified proteins across different spore formers resulted in a set of 13 coat proteins conserved across the spore formers and 12 exosporium proteins conserved in the B. cereus group, which could be tested for quick and easy detection or targeted in strategies aimed at removal of spores from surfaces.


Assuntos
Bacillus cereus/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Clostridioides difficile/metabolismo , Proteoma/metabolismo , Esporos Bacterianos/metabolismo , Bacillus cereus/fisiologia , Aderência Bacteriana , Clostridioides difficile/fisiologia , Farmacorresistência Bacteriana , Microbiologia de Alimentos , Peptidoglicano/metabolismo , Estrutura Terciária de Proteína
16.
Nat Commun ; 14(1): 3666, 2023 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-37380635

RESUMO

Green leaf volatiles (GLVs) are short-chain oxylipins that are emitted from plants in response to stress. Previous studies have shown that oral secretions (OS) of the tobacco hornworm Manduca sexta, introduced into plant wounds during feeding, catalyze the re-arrangement of GLVs from Z-3- to E-2-isomers. This change in the volatile signal however is bittersweet for the insect as it can be used by their natural enemies, as a prey location cue. Here we show that (3Z):(2E)-hexenal isomerase (Hi-1) in M. sexta's OS catalyzes the conversion of the GLV Z-3-hexenal to E-2-hexenal. Hi-1 mutants that were raised on a GLV-free diet showed developmental disorders, indicating that Hi-1 also metabolizes other substrates important for the insect's development. Phylogenetic analysis placed Hi-1 within the GMCß-subfamily and showed that Hi-1 homologs from other lepidopterans could catalyze similar reactions. Our results indicate that Hi-1 not only modulates the plant's GLV-bouquet but also functions in insect development.


Assuntos
Líquidos Corporais , Manduca , Animais , Filogenia , Catálise , Folhas de Planta
17.
J Biol Chem ; 286(50): 43506-14, 2011 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-22025617

RESUMO

Chemokines (chemotactic cytokines) can have direct antimicrobial activity, which is apparently related to the presence of a distinct positively charged patch on the surface. However, chemokines can retain antimicrobial activity upon linearization despite the loss of their positive patch, thus questioning the importance of this patch for activity. Thrombocidin-1 (TC-1) is a microbicidal protein isolated from human blood platelets. TC-1 only differs from the chemokine NAP-2/CXCL7 by a two-amino acid C-terminal deletion, but this truncation is crucial for antimicrobial activity. We assessed the structure-activity relationship for antimicrobial activity of TC-1. Reduction of the charge of the TC-1-positive patch by replacing lysine 17 with alanine reduced the activity against bacteria and almost abolished activity against the yeast Candida albicans. Conversely, augmentation of the positive patch by increasing charge density or size resulted in a 2-3-fold increased activity against Staphylococcus aureus, Escherichia coli, and Bacillus subtilis but did not substantially affect activity against C. albicans. Reduction of TC-1 resulted in loss of the folded conformation, but this disruption of the positive patch did not affect antimicrobial activity. Using overlapping 15-mer synthetic peptides, we demonstrate peptides corresponding to the N-terminal part of TC-1 to have similar antimicrobial activity as intact TC-1. Although we demonstrate that the positive patch is essential for activity of folded TC-1, unfolded TC-1 retained antimicrobial activity despite the absence of a positive patch. This activity is probably exerted by a linear peptide stretch in the N-terminal part of the molecule. We conclude that intact TC-1 and unfolded TC-1 exert antimicrobial activity via distinct structural elements.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Sequência de Aminoácidos , Anti-Infecciosos/metabolismo , Bacillus subtilis/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Dicroísmo Circular , Escherichia coli/efeitos dos fármacos , Humanos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Peptídeos/genética , Peptídeos/metabolismo , Dobramento de Proteína , Estrutura Secundária de Proteína , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade
18.
J Am Chem Soc ; 134(6): 2860-3, 2012 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-22280096

RESUMO

A chiral supramolecular ligand has been assembled and applied to the rhodium-catalyzed asymmetric hydroformylation of unfunctionalized internal alkenes. Spatial confinement of the metal center within a chiral pocket results in reversed regioselectivity and remarkable enantioselectivities.

19.
Physiol Plant ; 145(3): 426-39, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22289076

RESUMO

Sequential adaptation to nitrogen deprivation and ultimately to full starvation requires coordinated adjustment of cellular functions. We investigated changes in gene expression and cell physiology of the cyanobacterium Synechocystis PCC 6803 during 96 h of nitrogen starvation. During the first 6 h, the transcriptome showed activation of nitrogen uptake and assimilation systems and of the core nitrogen and carbon assimilation regulators. However, the nitrogen-deprived cells still grew at the same rate as the control and even showed transiently increased expression of phycobilisome genes. After 12 h, cell growth decreased and chlorosis started with degradation of the nitrogen-rich phycobilisomes. During this phase, the transcriptome showed suppression of genes for phycobilisomes, for carbon fixation and for de novo protein synthesis. Interestingly, photosynthetic activity of both photosystem I (PSI) and photosystem II was retained quite well. Excess electrons were quenched by the induction of terminal oxidase and hydrogenase genes, compensating for the diminished carbon fixation and nitrate reduction activity. After 48 h, the cells ceased most activities. A marked exception was the retained PSI gene transcription, possibly this supports the viability of Synechocystis cells and enables rapid recovery after relieving from nitrogen starvation. During early recovery, many genes changed expression, supporting the resumed cellular activity. In total, our results distinguished three phases during gradual nitrogen depletion: (1) an immediate response, (2) short-term acclimation and (3) long-term survival. This shows that cyanobacteria respond to nitrogen starvation by a cascade of physiological adaptations reflected by numerous changes in the transcriptome unfolding at different timescales.


Assuntos
Nitrogênio/metabolismo , Fotossíntese , Synechocystis/metabolismo , Aclimatação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Carbono/metabolismo , Transporte de Elétrons , Regulação Bacteriana da Expressão Gênica , Genes Bacterianos , Viabilidade Microbiana , Análise de Sequência com Séries de Oligonucleotídeos , Complexo de Proteína do Fotossistema I/genética , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/genética , Complexo de Proteína do Fotossistema II/metabolismo , Ficobilissomas/genética , Ficobilissomas/metabolismo , Synechocystis/genética , Synechocystis/crescimento & desenvolvimento , Fatores de Tempo , Transcriptoma
20.
Eukaryot Cell ; 10(8): 1071-81, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21622905

RESUMO

Fluconazole is a commonly used antifungal drug that inhibits Erg11, a protein responsible for 14α-demethylation during ergosterol synthesis. Consequently, ergosterol is depleted from cellular membranes and replaced by toxic 14α-methylated sterols, which causes increased membrane fluidity and drug permeability. Surface-grown and planktonic cultures of Candida albicans responded similarly to fluconazole at 0.5 mg/liter, showing reduced biomass formation, severely reduced ergosterol levels, and almost complete inhibition of hyphal growth. There was no evidence of cell leakage. Mass spectrometric analysis of the secretome showed that its composition was strongly affected and included 17 fluconazole-specific secretory proteins. Relative quantification of (14)N-labeled query walls relative to a reference standard mixture of (15)N-labeled yeast and hyphal walls in combination with immunological analysis revealed considerable fluconazole-induced changes in the wall proteome as well. They were, however, similar for both surface-grown and planktonic cultures. Two major trends emerged: (i) decreased incorporation of hypha-associated wall proteins (Als3, Hwp1, and Plb5), consistent with inhibition of hyphal growth, and (ii) increased incorporation of putative wall repair-related proteins (Crh11, Pga4, Phr1, Phr2, Pir1, and Sap9). As exposure to the wall-perturbing drug Congo red led to a similar response, these observations suggested that fluconazole affects the wall. In keeping with this, the resistance of fluconazole-treated cells to wall-perturbing compounds decreased. We propose that fluconazole affects the integrity of both the cellular membranes and the fungal wall and discuss its potential consequences for antifungal therapy. We also present candidate proteins from the secretome for clinical marker development.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Parede Celular/metabolismo , Fluconazol/farmacologia , Proteínas Fúngicas/metabolismo , Hifas/efeitos dos fármacos , Sequência de Aminoácidos , Candida albicans/crescimento & desenvolvimento , Candida albicans/metabolismo , Parede Celular/efeitos dos fármacos , Análise de Fourier , Hifas/crescimento & desenvolvimento , Hifas/metabolismo , Espectrometria de Massas , Dados de Sequência Molecular , Fragmentos de Peptídeos/química
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