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1.
J Hazard Mater ; 443(Pt A): 130186, 2023 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-36265381

RESUMO

Exopolysaccharides (EPS) are macromolecules with environment beneficial properties. Currently, numerous studies focus on the absorption of heavy metals by EPS, but less attention has been paid to the effects of EPS on the plants. This study explored the effects of EPS from Lactobacillus plantarum LPC-1 on the structure and function of cell walls in rice seedling roots under cadmium (Cd) stress. The results showed that EPS could regulate the remodeling process of the cell walls of rice roots. EPS affects the synthesis efficiency and the content of the substances that made up the cell wall, and thus plays an essential role in limiting the uptake and transport of Cd in rice root. Furthermore, EPS could induce plant resistance to heavy metals by regulating the lignin biosynthesis pathway in rice roots. Finally, the cell wall remodeling induced by EPS likely contributes to plant stress responses by activating the reactive oxygen species (ROS) signaling.


Assuntos
Metais Pesados , Oryza , Oryza/metabolismo , Cádmio/metabolismo , Plântula/metabolismo , Raízes de Plantas/metabolismo , Parede Celular/metabolismo , Metais Pesados/metabolismo , Plantas/metabolismo
2.
Methods Mol Biol ; 2566: 269-279, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36152259

RESUMO

The plant cell wall comprises various types of macromolecules whose abundance and spatial distribution change dynamically and are crucial for plant architecture. High-resolution live cell imaging of plant cell wall components is, therefore, a powerful tool for plant cell biology and plant developmental biology. To acquire suitable data, the experimental setup for staining and imaging of non-fixed samples must be straightforward and avoid creating stress-induced artifacts. We present a detailed sample preparation and live image acquisition protocol for fluorescence visualization of cell wall components using commercially available probes and stains.


Assuntos
Celulose , Pectinas , Membrana Celular/metabolismo , Parede Celular/metabolismo , Celulose/metabolismo , Pectinas/metabolismo , Células Vegetais/metabolismo
3.
Food Chem ; 399: 133997, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36037687

RESUMO

The effect of hydrogen-rich water (HRW) treatment on softening, cell wall components and cell wall metabolic genes in okras after harvest was studied. The results showed that HRW treatment could maintain fruit firmness and delay softening, thereby prolonging shelf life in okras during storage. The treated okras displayed significantly lower levels water- and chelate-soluble pectins while higher contents of Na2CO3-soluble pectin, hemicellulose and cellulose. The cell wall biosynthesis was maintained by HRW treatment via up-regulating genes involved in biosynthesis of pectin, hemicellulose and cellulose at the beginning of storage. On the contrary, the treatment could inhibit the cell wall disassembly due to the down-regulation of numerous cell wall degradative genes including AePME, AeGAL and AeCX at the end of storage. Taken together, our results suggested that HRW treatment delayed softening and extended shelf life in postharvest okras through modifying cell wall biosynthesis and disassembly at different times of storage.


Assuntos
Abelmoschus , Frutas , Abelmoschus/metabolismo , Parede Celular/metabolismo , Celulose/metabolismo , Frutas/metabolismo , Hidrogênio/farmacologia , Pectinas/metabolismo , Água/metabolismo
4.
J Integr Plant Biol ; 64(1): 73-86, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34845845

RESUMO

Wood is produced by the accumulation of secondary xylem via proliferation and differentiation of the cambium cells in woody plants. Identifying the regulators involved in this process remains a challenging task. In this study, we isolated PagSAG101a, the homolog of Arabidopsis thaliana SAG101, from a hybrid poplar (Populus alba × Populus glandulosa) clone 84K and investigated its role in secondary xylem development. PagSAG101a was expressed predominantly in lignified stems and localized in the nucleus. Compared with non-transgenic 84K plants, transgenic plants overexpressing PagSAG101a displayed increased plant height, internode number, stem diameter, xylem width, and secondary cell wall thickness, while opposite phenotypes were observed for PagSAG101a knock-out plants. Transcriptome analyses revealed that differentially expressed genes were enriched for those controlling cambium cell division activity and subsequent secondary cell wall deposition during xylem formation. In addition, the tandem CCCH zinc finger protein PagC3H17, which positively regulates secondary xylem width and secondary wall thickening in poplar, could bind to the promoter of PagSAG101a and mediate the regulation of xylem differentiation. Our results support that PagSAG101a, downstream of PagC3H17, functions in wood development.


Assuntos
Populus , Câmbio/genética , Câmbio/metabolismo , Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Populus/genética , Populus/metabolismo , Madeira/genética , Xilema/genética
5.
Commun Biol ; 5(1): 1228, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36369270

RESUMO

Bacterial cell division is a complex, dynamic process that requires multiple protein components to orchestrate its progression. Many division proteins are highly conserved across bacterial species alluding to a common, basic mechanism. Central to division is a transmembrane trimeric complex involving DivIB, DivIC and FtsL in Gram-positives. Here, we show a distinct, essential role for DivIC in division and survival of Staphylococcus aureus. DivIC spatially regulates peptidoglycan synthesis, and consequently cell wall architecture, by influencing the recruitment to the division septum of the major peptidoglycan synthetases PBP2 and FtsW. Both the function of DivIC and its recruitment to the division site depend on its extracellular domain, which interacts with the cell wall via binding to wall teichoic acids. DivIC facilitates the spatial and temporal coordination of peptidoglycan synthesis with the developing architecture of the septum during cell division. A better understanding of the cell division mechanisms in S. aureus and other pathogenic microorganisms can provide possibilities for the development of new, more effective treatments for bacterial infections.


Assuntos
Peptidoglicano , Staphylococcus aureus , Staphylococcus aureus/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Membrana/metabolismo , Divisão Celular , Parede Celular/metabolismo
6.
Int J Mol Sci ; 23(21)2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36361997

RESUMO

Secondary cell wall thickening plays a crucial role in plant growth and development. Diploid woodland strawberry (Fragaria vesca) is an excellent model for studying fruit development, but its molecular control of secondary wall thickening is largely unknown. Previous studies have shown that Arabidopsis NAC secondary wall thickening promoting factor1 (AtNST1) and related proteins are master regulators of xylem fiber cell differentiation in multiple plant species. In this study, a NST1-like gene, FvNST1b, was isolated and characterized from strawberry. Sequence alignment and phylogenetic analysis showed that the FvNST1b protein contains a highly conserved NAC domain, and it belongs to the same family as AtNST1. Overexpression of FvNST1b in wild-type Arabidopsis caused extreme dwarfism, induced ectopic thickening of secondary walls in various tissues, and upregulated the expression of genes related to secondary cell wall synthesis. In addition, transient overexpression of FvNST1b in wild-type Fragaria vesca fruit produced cells resembling tracheary elements. These results suggest that FvNST1b positively regulates secondary cell wall formation as orthologous genes from other species.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fragaria , Fragaria/genética , Fragaria/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Filogenia , Fatores de Transcrição/metabolismo , Parede Celular/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
7.
Int J Mol Sci ; 23(21)2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36362232

RESUMO

Aluminized acidic soil can damage Eucalyptus roots and limit tree growth, hindering the productivity of Eucalyptus plantations. At present, the negative impacts of elevated aluminum (Al) on the cell morphology and cell wall properties of Eucalyptus root tip are still unclear. In order to investigate the responses of two different tolerant clones, Eucalyptus urophylla (G4) and Eucalyptus grandis × Eucalyptus urophylla (G9), to Al toxicity, seedling roots were treated hydroponically with an Al solution, and the polysaccharide content in the root tip cell wall and the characteristics of programmed cell death were studied. The results show that the distribution of Al was similar in both clones, although G9 was found to be more tolerant to Al toxicity than G4. The Al3+ uptake of pectin in root tip cell walls was significantly higher in G4 than in G9. The root tip in G4 was obviously damaged, enlarged, thickened, and shorter; the root crown cells were cracked and fluffy; and the cell elongation area was squeezed. The lower cell wall polysaccharide content and PME activity may result in fewer carboxylic groups in the root tip cell wall to serve as Al-binding sites, which may explain the stronger Al resistance of G9 than G4. The uptake of nitrogen and potassium in G4 was significantly reduced after aluminum application and was lower than in G9. Al-resistant Eucalyptus clones may have synergistic pleiotropic effects in resisting high aluminum-low phosphorus stress, and maintaining higher nitrogen and potassium levels in roots may be an important mechanism for effectively alleviating Al toxicity.


Assuntos
Alumínio , Eucalyptus , Alumínio/metabolismo , Eucalyptus/metabolismo , Raízes de Plantas/metabolismo , Parede Celular/metabolismo , Polissacarídeos/metabolismo , Nutrientes , Células Clonais , Nitrogênio/metabolismo , Potássio/metabolismo
8.
Elife ; 112022 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-36350124

RESUMO

Bacteria of the order Corynebacteriales including pathogens such as Mycobacterium tuberculosis and Corynebacterium diphtheriae are characterized by their complex, multi-layered envelope. In addition to a peptidoglycan layer, these organisms possess an additional polysaccharide layer made of arabinogalactan and an outer membrane layer composed predominantly of long-chain fatty acids called mycolic acids. This so-called mycolata envelope structure is both a potent barrier against antibiotic entry into cells and a target of several antibacterial therapeutics. A better understanding of the mechanisms underlying mycolata envelope assembly therefore promises to reveal new ways of disrupting this unique structure for the development of antibiotics and antibiotic potentiators. Because they engage with receptors on the cell surface during infection, bacteriophages have long been used as tools to uncover important aspects of host envelope assembly. However, surprisingly little is known about the interactions between Corynebacteriales phages and their hosts. We therefore made use of the phages Cog and CL31 that infect Corynebacterium glutamicum (Cglu), a model member of the Corynebacteriales, to discover host factors important for phage infection. A high-density transposon library of Cglu was challenged with these phages followed by transposon sequencing to identify resistance loci. The analysis identified an important role for mycomembrane proteins in phage infection as well as components of the arabinogalactan and mycolic acid synthesis pathways. Importantly, the approach also implicated a new gene (cgp_0396) in the process of arabinogalactan modification and identified a conserved new factor (AhfA, Cpg_0475) required for mycolic acid synthesis in Cglu.


Assuntos
Bacteriófagos , Corynebacterium glutamicum , Ácidos Micólicos/metabolismo , Bacteriófagos/genética , Bacteriófagos/metabolismo , Parede Celular/metabolismo , Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Antibacterianos/farmacologia , Antibacterianos/metabolismo
10.
Proc Natl Acad Sci U S A ; 119(45): e2209111119, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36322746

RESUMO

Surface layers (S-layers) are highly ordered coats of proteins localized on the cell surface of many bacterial species. In these structures, one or more proteins form elementary units that self-assemble into a crystalline monolayer tiling the entire cell surface. Here, the cell envelope of the radiation-resistant bacterium Deinococcus radiodurans was studied by cryo-electron microscopy, finding the crystalline regularity of the S-layer extended into the layers below (outer membrane, periplasm, and inner membrane). The cell envelope appears to be highly packed and resulting from a three-dimensional crystalline distribution of protein complexes organized in close continuity yet allowing a certain degree of free space. The presented results suggest how S-layers, at least in some species, are mesoscale assemblies behaving as structural and functional scaffolds essential for the entire cell envelope.


Assuntos
Deinococcus , Deinococcus/metabolismo , Microscopia Crioeletrônica , Proteínas de Bactérias/metabolismo , Parede Celular/metabolismo , Membrana Celular/metabolismo
11.
Front Cell Infect Microbiol ; 12: 976924, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36211971

RESUMO

The cell wall (CW) of fungi exhibits a complex structure and a characteristic chemical composition consisting almost entirely of interacting crystalline and amorphous polysaccharides. These are synthesized by a number of sugar polymerases and depolymerases encoded by a high proportion of the fungal genome (for instance, 20% in Saccharomyces cerevisiae). These enzymes act in an exquisitely coordinated process to assemble the tridimensional and the functional structure of the wall. Apart from playing a critical role in morphogenesis, cell protection, viability and pathogenesis, the CW represents a potential target for antifungals as most of its constituents do not exist in humans. Chitin, ß-glucans and cellulose are the most frequent crystalline polymers found in the fungal CW. The hexosamine biosynthesis pathway (HBP) is critical for CW elaboration. Also known as the Leloir pathway, this pathway ends with the formation of UDP-N-GlcNAc after four enzymatic steps that start with fructose-6-phosphate and L-glutamine in a short deviation of glycolysis. This activated aminosugar is used for the synthesis of a large variety of biomacromolecules in a vast number of organisms including bacteria, fungi, insects, crustaceans and mammalian cells. The first reaction of the HBP is catalyzed by GlcN-6-P synthase (L-glutamine:D-fructose-6-phosphate amidotransferase; EC 2.6.1.16), a critical enzyme that has been considered as a potential target for antifungals. The enzyme regulates the amount of cell UDP-N-GlcNAc and in eukaryotes is feedback inhibited by the activated aminosugar and other factors. The native and recombinant forms of GlcN-6-P synthase has been purified and characterized from both prokaryotic and eukaryotic organisms and demonstrated its critical role in CW remodeling and morphogenesis after exposure of some fungi to agents that stress the cell surface by interacting with wall polymers. This review deals with some of the cell compensatory responses of fungi to wall damage induced by Congo Red and Calcofluor White.


Assuntos
Sporothrix , beta-Glucanas , Animais , Antifúngicos , Benzenossulfonatos , Parede Celular/metabolismo , Celulose , Quitina , Vermelho Congo , Glutamina , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/genética , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/metabolismo , Hexosaminas/análise , Hexosaminas/metabolismo , Humanos , Mamíferos/metabolismo , Polímeros/análise , Sporothrix/metabolismo , Açúcares , Difosfato de Uridina , beta-Glucanas/análise
12.
Elife ; 112022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36206043

RESUMO

How does a protein at the cell wall determine if a newly encountered fungus is safe to fuse with?


Assuntos
Neurospora crassa , Parede Celular/metabolismo , Neurospora crassa/metabolismo
13.
J Plant Physiol ; 278: 153830, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36195007

RESUMO

Pits in ray parenchyma cells are important to understand the functional anatomy of the ray parenchyma network in the xylem but have been less studied. Herein, pits in two types of ray parenchyma cells, contact cells and isolation cells, across different developmental stages were qualitatively studied using 48-year-old Populus tomentosa trees. The timing of differentiation and death was determined by histochemical staining and polarized light microscopy. The dimension, shape and density of pits as well as cell wall thickness were measured using SEM and optical microscopy images of semi-thin radial sections and macerated ray parenchyma cells, and analyzed by multi-factor analyses of variance. Results showed that secondary wall thickening and lignification of contact cells begun near the cambium, contrarily those of isolation cells have started until the transition zone. But even in the sapwood, contact cell walls were still much thinner than isolation cell walls. Moreover, district anatomical adaptions of pits during the xylem differentiation were present between horizontal walls and tangential walls, between contact cells and isolation cells. Ray pits were simple to slightly bordered, whereas sieve-like pits were only shown on tangential walls of isolation cells. Pit density of horizontal walls was similar between contact cells and isolation cells, nevertheless greater pits were present on tangential walls, especially for isolation cells. In addition, pits of ray parenchyma cells in the heartwood were smaller and more bordered than those in the sapwood, particularly on the horizontal walls. Moreover, isolation cells had pits with the smaller dimensions, greater pits on the tangential walls, more bordered pits on horizontal walls, as well as longer and narrower cell morphology with much thicker cell walls than contact cells. To a certain extent, all these anatomical adaptations were developed to ensure distinct functions of the two types of ray parenchyma cells in the xylem and finally to support tree growth in demand.


Assuntos
Populus , Diferenciação Celular , Parede Celular/metabolismo , Árvores/fisiologia , Xilema/metabolismo
14.
Int J Mol Sci ; 23(19)2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-36232332

RESUMO

The cell wall integrity pathway (CWI) is a MAPK-mediated signaling route essential for yeast cell response to cell wall damage, regulating distinct aspects of fungal physiology. We have recently proven that the incorporation of a genetic circuit that operates as a signal amplifier into this pathway allows for the identification of novel elements involved in CWI signaling. Here, we show that the strong growth inhibition triggered by pathway hyperactivation in cells carrying the "Integrity Pathway Activation Circuit" (IPAC) also allows the easy identification of new stimuli. By using the IPAC, we have found various chemical agents that activate the CWI pathway, including the aminoglycoside neomycin. Cells lacking key components of this pathway are sensitive to this antibiotic, due to the disruption of signaling upon neomycin stimulation. Neomycin reduces both phosphatidylinositol-4,5-bisphosphate (PIP2) availability at the plasma membrane and myriocin-induced TORC2-dependent Ypk1 phosphorylation, suggesting a strong interference with plasma membrane homeostasis, specifically with PIP2. The neomycin-induced transcriptional profile involves not only genes related to stress and cell wall biogenesis, but also to amino acid metabolism, reflecting the action of this antibiotic on the yeast ribosome.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Aminoácidos/metabolismo , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Membrana Celular/metabolismo , Parede Celular/metabolismo , Fosfatos de Inositol/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neomicina/farmacologia , Fosfatidilinositóis/metabolismo , Fosforilação , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
15.
Plant Physiol Biochem ; 191: 67-77, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36195034

RESUMO

Ammonium promotes rice P uptake and reutilization better than nitrate, under P starvation conditions; however, the underlying mechanism remains unclear. In this study, ammonium treatment significantly increased putrescine and ethylene content in rice roots under P deficient conditions, by increasing the protein content of ornithine decarboxylase and 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase compared with nitrate treatment. Ammonium treatment increased rice root cell wall P release by increasing pectin content and pectin methyl esterase (PME) activity, increased rice shoot cell membrane P release by decreasing phosphorus-containing lipid components, and maintained internal P homeostasis by increasing OsPT2/6/8 expression compared with nitrate treatment. Ammonium also improved external P uptake by regulating root morphology and increased rice grain yield by increasing the panicle number compared with nitrate treatment. The application of putrescine and ethylene synthesis precursor ACC further improved the above process. Our results demonstrate for the first time that ammonium increases rice P acquisition, reutilization, and homeostasis, and rice grain yield, in a putrescine- and ethylene-dependent manner, better than nitrate, under P starvation conditions.


Assuntos
Compostos de Amônio , Oryza , Compostos de Amônio/metabolismo , Compostos de Amônio/farmacologia , Membrana Celular/metabolismo , Parede Celular/metabolismo , Esterases/metabolismo , Etilenos/metabolismo , Lipídeos , Nitratos/metabolismo , Ornitina Descarboxilase/metabolismo , Oryza/metabolismo , Oxirredutases/metabolismo , Pectinas/metabolismo , Fósforo/metabolismo , Raízes de Plantas/metabolismo , Putrescina/metabolismo
16.
Nat Commun ; 13(1): 6258, 2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36271009

RESUMO

Lytic polysaccharide monooxygenase (LPMO) supports biomass hydrolysis by increasing saccharification efficiency and rate. Recent studies demonstrate that H2O2 rather than O2 is the cosubstrate of the LPMO-catalyzed depolymerization of polysaccharides. Some studies have questioned the physiological relevance of the H2O2-based mechanism for plant cell wall degradation. This study reports the localized and time-resolved determination of LPMO activity on poplar wood cell walls by measuring the H2O2 concentration in their vicinity with a piezo-controlled H2O2 microsensor. The investigated Neurospora crassa LPMO binds to the inner cell wall layer and consumes enzymatically generated H2O2. The results point towards a high catalytic efficiency of LPMO at a low H2O2 concentration that auxiliary oxidoreductases in fungal secretomes can easily generate. Measurements with a glucose microbiosensor additionally demonstrate that LPMO promotes cellobiohydrolase activity on wood cell walls and plays a synergistic role in the fungal extracellular catabolism and in industrial biomass degradation.


Assuntos
Oxigenases de Função Mista , Madeira , Oxigenases de Função Mista/metabolismo , Madeira/metabolismo , Celulose 1,4-beta-Celobiosidase , Peróxido de Hidrogênio/metabolismo , Proteínas Fúngicas/metabolismo , Polissacarídeos/metabolismo , Oxirredutases , Parede Celular/metabolismo , Glucose
17.
Ecotoxicol Environ Saf ; 246: 114178, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36244168

RESUMO

Plant root growth is inhibited markedly by aluminium (Al) even at micromolar concentration and Al is mainly accumulated in plant roots outer layer cell walls. But the underlying reason for this asymmetric transverse distribution is unknown. In this study, two wheat (Triticum aestivum L.) genotypes ET8 and ES8 differing in Al resistance were investigated by hydroculture. The Al-tolerant ET8 expressed a higher root elongation rate (RER) than Al-sensitive ES8 under Al stress. Morphological examination showed symptoms such as root surface ruptures were observed in ET8 and ES8, with ES8 being more obvious. The cation exchange capacity (CEC) values of root tips of ES8 under different Al concentrations are higher than those of ET8. The sensitive genotype ES8 accumulated more Al than ET8 in plant apical root tips as well as cell walls. Under 48 h Al exposure, the root cell wall pectin concentration was increased with a higher magnitude in ES8 than in ET8. The functional groups on ET8 and ES8 roots outer layer and inner cells were investigated by Fourier transform infrared spectrometry (FTIR) under Al stress. The FTIR spectra of selected examined areas showed that the characteristic absorption peaks were located at 1692, 2920, and 3380 cm-1. The outer layer cells had stronger peaks than inner cells at wavenumber 1680-1740 cm-1, indicating root outer layer cells contain more carboxyls in both ET8 and ES8. The results demonstrate that Al transverse distribution on plants apical root cross section is likely influenced by functional groups such as negatively charged carboxylic acid.


Assuntos
Alumínio , Triticum , Triticum/genética , Triticum/metabolismo , Alumínio/toxicidade , Alumínio/metabolismo , Raízes de Plantas/metabolismo , Parede Celular/metabolismo , Pectinas/metabolismo
18.
Bioresour Technol ; 365: 128132, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36252752

RESUMO

Sustainable bioproduction usingcarbon neutral feedstocks, especially lignocellulosic biomass, has attracted increasing attention due to concern over climate change and carbon reduction. Consolidated bioprocessing (CBP) of lignocellulosic biomass using recombinantyeast of Saccharomyces cerevisiaeis a promising strategy forlignocellulosic biorefinery. However, the economic viability is restricted by low enzyme secretion levels.For more efficient CBP, MIG1spsc01isolated from the industrial yeast which encodes the glucose repression regulator derivative was overexpressed. Increased extracellular cellobiohydrolase (CBH) activity was observed with unexpectedly decreased cell wall integrity. Further studies revealed that disruption ofCWP2, YGP1, andUTH1,which are functionally related toMIG1spsc01, also enhanced CBH secretion. Subsequently, improved cellulase production was achieved by simultaneous disruption ofYGP1and overexpression ofSED5, which remarkably increased extracellular CBH activity of 2.2-fold over the control strain. These results provide a novel strategy to improve the CBP yeast for bioconversion of carbon neutral biomass.


Assuntos
Celulase , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Biomassa , Carbono/metabolismo , Celulase/metabolismo , Celulose 1,4-beta-Celobiosidase/genética , Celulose 1,4-beta-Celobiosidase/metabolismo , Parede Celular/metabolismo , Fermentação
19.
Front Cell Infect Microbiol ; 12: 977157, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36268228

RESUMO

Increased levels of 17-ß estradiol (E2) due to pregnancy in young women or to hormonal replacement therapy in postmenopausal women have long been associated with an increased risk of yeast infections. Nevertheless, the effect underlying the role of E2 in Candida albicans infections is not well understood. To address this issue, functional, transcriptomic, and metabolomic analyses were performed on C. albicans cells subjected to temperature and serum induction in the presence or absence of E2. Increased filament formation was observed in E2 treated cells. Surprisingly, cells treated with a combination of E2 and serum showed decreased filament formation. Furthermore, the transcriptomic analysis revealed that serum and E2 treatment is associated with downregulated expression of genes involved in filamentation, including HWP1, ECE1, IHD1, MEP1, SOD5, and ALS3, in comparison with cells treated with serum or estrogen alone. Moreover, glucose transporter genes HGT20 and GCV2 were downregulated in cells receiving both serum and E2. Functional pathway enrichment analysis of the differentially expressed genes (DEGs) suggested major involvement of E2 signaling in several metabolic pathways and the biosynthesis of secondary metabolites. The metabolomic analysis determined differential secretion of 36 metabolites based on the different treatments' conditions, including structural carbohydrates and fatty acids important for hyphal cell wall formation such as arabinonic acid, organicsugar acids, oleic acid, octadecanoic acid, 2-keto-D-gluconic acid, palmitic acid, and steriacstearic acid with an intriguing negative correlation between D-turanose and ergosterol under E2 treatment. In conclusion, these findings suggest that E2 signaling impacts the expression of several genes and the secretion of several metabolites that help regulate C. albicans morphogenesis and virulence.


Assuntos
Candida albicans , Hifas , Feminino , Humanos , Parede Celular/metabolismo , Ergosterol/metabolismo , Ácidos Graxos/metabolismo , Estrogênios/farmacologia , Polissacarídeos/metabolismo , Estradiol/farmacologia , Estradiol/metabolismo , Ácidos Esteáricos/metabolismo , Ácidos Esteáricos/farmacologia , Proteínas Facilitadoras de Transporte de Glucose/genética , Proteínas Facilitadoras de Transporte de Glucose/metabolismo , Proteínas Facilitadoras de Transporte de Glucose/farmacologia , Carboidratos , Ácidos Palmíticos/metabolismo , Ácidos Palmíticos/farmacologia , Ácidos Oleicos/metabolismo , Ácidos Oleicos/farmacologia , Regulação Fúngica da Expressão Gênica
20.
Front Cell Infect Microbiol ; 12: 984955, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36275016

RESUMO

The human pathogen Haemophilus influenzae causes respiratory tract infections and is commonly associated with prolonged carriage in patients with chronic obstructive pulmonary disease. Production of outer membrane vesicles (OMVs) is a ubiquitous phenomenon observed in Gram-negative bacteria including H. influenzae. OMVs play an important role in various interactions with the human host; from neutralization of antibodies and complement activation to spread of antimicrobial resistance. Upon vesiculation certain proteins are found in OMVs and some proteins are retained at the cell membrane. The mechanism for this phenomenon is not fully elucidated. We employed mass spectrometry to study vesiculation and the fate of proteins in the outer membrane. Functional groups of proteins were differentially distributed on the cell surface and in OMVs. Despite its supposedly periplasmic and outer membrane location, we found that the peptidoglycan synthase-activator Lipoprotein A (LpoA) was accumulated in OMVs relative to membrane fractions. A mutant devoid of LpoA lost its fitness as revealed by growth and electron microscopy. Furthermore, high-pressure liquid chromatography disclosed a lower concentration (55%) of peptidoglycan in the LpoA-deficient H. influenzae compared to the parent wild type bacterium. Using an LpoA-mNeonGreen fusion protein and fluorescence microscopy, we observed that LpoA was enriched in "foci" in the cell envelope, and further located in the septum during cell division. To define the fate of LpoA, C-terminally truncated LpoA-variants were constructed, and we found that the LpoA C-terminal domain promoted optimal transportation to the OMVs as revealed by flow cytometry. Taken together, our study highlights the importance of LpoA for H. influenzae peptidoglycan biogenesis and provides novel insights into cell wall integrity and OMV production.


Assuntos
Anti-Infecciosos , Haemophilus influenzae , Humanos , Haemophilus influenzae/metabolismo , Domínios Proteicos , Proteínas da Membrana Bacteriana Externa/metabolismo , Lipoproteína(a)/metabolismo , Peptidoglicano/metabolismo , Parede Celular/metabolismo , Anti-Infecciosos/metabolismo
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