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Fe deficiency is a major challenge that limits agricultural productivity and is a serious human health concern worldwide. Under iron-limiting conditions soil microorganisms produce siderophores, that chelates Fe3+ (ferric) and make it available to the plants. Selection of efficient siderophore producing bacteria and establishing their role in enhancing iron uptake is a strategic approach for improving plant nutrition. Hence 3 efficient isolates Pantoea agglomerans, Pseudomonas plecoglossida and Lactococcus lactis, selected from a repository of 154 bacteria, producing catecholate, hydroxamate and carboxylate siderophores, respectively, were assessed for Fe chelation efficiency using 59Fe and their role in plant biometric parameters, Fe uptake and antioxidant enzymes with tomato (Strategy I) and wheat (Strategy II) test plants under hydroponic system. Cell-free siderophore preparation (Sid) improved plant parameters and iron nutrition more efficiently than bacterial inoculants. Pantoea agglomerans was proven best as its 59Fe-bound siderophore complex showed the highest uptake of 4.25 and 1.59 Bq plant-1 in wheat and tomato, respectively. Further, the Fe-starved plants (1 µm Fe-EDTA) showed around two-fold higher 59Fe uptake than those raised under Fe-sufficient condition (100 µm Fe-EDTA). Results indicated that probably the bacterial mediated iron translocation in plants is Strategy III, complementing both Strategy I and II by facilitating higher availability of chelated Fe to plant reductases directly and/or through ligand exchange with phytosiderophores, respectively. This study highlights the need for integration of siderophore based formulations in INM strategies for enhancing plant iron content to address the Fe deficiency challenge of the soil and human nutrition.
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Sideróforos , Solanum lycopersicum , Bacterias , Humanos , Hierro , SueloRESUMEN
BACKGROUND: Cellulose, the most versatile biomolecule on earth, is available in large quantities from plants. However, cellulose in plants is accompanied by other polymers like hemicellulose, lignin, and pectin. On the other hand, pure cellulose can be produced by some microorganisms, with the most active producer being Acetobacter xylinum. A. senengalensis is a gram-negative, obligate aerobic, motile coccus, isolated from Mango fruits in Senegal, capable of utilizing a variety of sugars and produce cellulose. Besides, the production is also influenced by other culture conditions. Previously, we isolated and identified A. senengalensis MA1, and characterized the bacterial cellulose (BC) produced. RESULTS: The maximum cellulose production by A. senengalensis MA1 was pre-optimized for different parameters like carbon, nitrogen, precursor, polymer additive, pH, temperature, inoculum concentration, and incubation time. Further, the pre-optimized parameters were pooled, and the best combination was analyzed by using Central Composite Design (CCD) of Response Surface Methodology (RSM). Maximum BC production was achieved with glycerol, yeast extract, and PEG 6000 as the best carbon and nitrogen sources, and polymer additive, respectively, at 4.5 pH and an incubation temperature of 33.5 °C. Around 20% of inoculum concentration gave a high yield after 30 days of inoculation. The interactions between culture conditions optimized by CCD included alterations in the composition of the HS medium with 50 mL L- 1 of glycerol, 7.50 g L- 1 of yeast extract at pH 6.0 by incubating at a temperature of 33.5 °C along with 7.76 g L- 1 of PEG 6000. This gave a BC yield of wet weight as 469.83 g L- 1. CONCLUSION: The optimized conditions of growth medium resulted in enhanced production of bacterial cellulose by A. senegalensis MA1, which is around 20 times higher than that produced using an unoptimized HS medium. Further, the cellulose produced can be used in food and pharmaceuticals, for producing high-quality paper, wound dressing material, and nanocomposite films for food packaging.
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Acetobacter/metabolismo , Técnicas de Cultivo de Célula/métodos , Celulosa/biosíntesis , Medios de Cultivo/química , Acetobacter/crecimiento & desarrollo , Carbono , Gluconacetobacter xylinus , Glicerol , Concentración de Iones de Hidrógeno , Nitrógeno , TemperaturaRESUMEN
The ability to control the growth of materials with nanosized precision as well as a complex hollow morphology provides rationale for the study of systems comprising both characteristics. This study explores the design of TiO2 hollow nanotube shells deposited by atomic layer deposition (ALD) on vertically aligned SnO2 nanorods grown using the vapor-liquid-solid technique. The sacrificial template approach in combination with highly conformal coating advantages of ALD resulted in a highly reproducible method to create a large surface area covered by TiO2-protected SnO2 nanorods, which are about 60-100 nm in diameter and approximately 1 µm in length. ZnO was used as a sacrificial layer to create a 30 nm gap between SnO2 nanorods and 10 nm of TiO2 shells. Chemical etching of the sacrificial layer was used to create the desired hollow nanocomposite. A coin half-cell battery has been assembled using the TiO2-protected SnO2 nanorods as an anode electrode and lithium foil as a counter electrode and tested for lithium storage during 70 cycles of charge/discharge in a range of 0.5-2.5 V. The TiO2 hollow shell functioned as a good and robust enhancer for both absolute capacity and current rate capabilities of vertically aligned SnO2 nanorods; an improvement in cyclic stability was also observed. This advanced self-standing hollow configuration provides several unique advantages for energy storage device applications including enhanced lithiation for superior energy storage performance.
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INTRODUCTION: Alginate is a versatile, irreversible hydrocolloid impression material, which is cost-effective and forms an essential component in dental practice. For elevating the hardness of the cast models, hardeners are combined with stone. Hence, we planned the present study to evaluate the impact of altering the time of contact between alginate and stone after various interim periods. MATERIALS AND METHODS: The present study included the assessment of impact of time of contact between alginate and stone by the construction of 90 casts using a cylinder model. Two bisecting lines were marked and were named as y and y'. These lines were used for testing the dimensional stability. Using chemically cured acrylic resin, the construction of ten special trays was done. All the impression casts were randomly divided into two study groups, with 45 casts in each group-group I: control group, casts were removed after 60 minutes; group II: study group, casts were removed after 9 hours. A digital caliper was used for measuring the dimensional stability of the cast. All the data were collected and analyzed. RESULTS: In the specimens of the control group (group I) and the study group (group II), the mean dimensions from y to y' were found to be 17.54 and 17.95 respectively. The mean reading of hardness in the control group and study group was found to be 0.59 and 0.20 respectively. In groups I and II, the number of specimens showing clarity of two lines (X and X") was 0 and 5 respectively. CONCLUSION: There was no change in the dimensional stability of the dental stone model when the contact time was increased. CLINICAL SIGNIFICANCE: Within certain limits, the contact time between alginate and stone can be altered without significantly altering the properties of the cast.
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Alginatos/metabolismo , Sulfato de Calcio/metabolismo , Modelos Dentales , Técnica de Colado Dental , Materiales de Impresión Dental/metabolismo , Ácido Glucurónico/metabolismo , Ácidos Hexurónicos/metabolismo , Humanos , Técnicas In Vitro , Factores de TiempoRESUMEN
BACKGROUND: Luting agents used to fix artificial prostheses, such as fixed partial denture (FPD) to tooth are basically viscous in nature and show chemical reaction for fixation. Postcementation hypersensitivity is a frequent complaint of patients. The present study was conducted to compare postcementation hypersensitivity with zinc phosphate and self-adhesive resin in complete coverage crown. MATERIALS AND METHODS: This study included 30 patients in which 60 porcelein fused to metal crowns was placed. Two metal crowns were placed in each patient in nonantagonis-tic contralateral quadrants. First crown was cemented with zinc phosphate cement, while the other was cemented with self-adhesive resin. Hypersensitivity was evaluated by visual analog scale (VAS) score and by clinical test. For clinical evaluation of sensitivity, hot and cold water was applied to the cervical margin of restoration for 5 seconds and response was recorded. RESULTS: This study consisted of 30 patients in which 60 crowns were given. There was no statistical difference in VAS score of mastication in zinc phosphate cement recorded at baseline, 1 week, 4 weeks, 6 months, 1 year, and 2 years (p > 0.05). Cold response also did not show a significant difference at six time points. Warm response showed slight decrease in subsequent time points but was nonsignificant (p > 0.05). Similarly, with self-adhesive resin cement, VAS score during mastication, hot and cold response was statistically nonsignificant (p > 0.05). CONCLUSION: Postcementation hypersensitivity is a frequent complaint that patient may experience. However, we found no statistically significant difference in both cements tested. CLINICAL SIGNIFICANCE: Postcementation hypersensitivity is an unpleasant sensation experienced by patients. This may affect the success of any prosthesis. Thus, selection of luting agent for cementation plays an important role to eliminate this symptom.
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Cerámica/uso terapéutico , Coronas , Dermatitis por Contacto/etiología , Fosfatos/uso terapéutico , Cementos de Resina/uso terapéutico , Compuestos de Zinc/uso terapéutico , Cerámica/efectos adversos , Coronas/efectos adversos , Cementos Dentales/efectos adversos , Cementos Dentales/uso terapéutico , Humanos , Fosfatos/efectos adversos , Estudios Prospectivos , Cementos de Resina/efectos adversos , Compuestos de Zinc/efectos adversosRESUMEN
ZnO has intrinsic semiconductor conductivity because of an unintentional doping mechanism resulting from the growth process that is mainly attributable to oxygen vacancies (VO) positioned in the bandgap. ZnO has multiple electronic states that depend on the number of vacancies and the charge state of each vacancy. In addition to the individual electron states, the vacancies have different vibrational states. We developed a high-temperature precursor vapor mask technique using Al2O3 to pattern the atomic layer deposition of ZnO and Al:ZnO layers on ZnO-based substrates. This technique was used to create a memristor device based on Al:ZnO thin films having metallic and semiconducting and insulating transport properties ZnO. We demonstrated that adding combination of Al2O3 and TiO2 barrier layers improved the resistive switching behavior. The change in the resistance between the high- and low-resistivity states of the memristor with a combination of Al2O3 and TiO2 was approximately 157%. The devices were exposed to laser light from three different laser diodes. The 450 nm laser diode noticeably affected the combined Al2O3 and TiO2 barrier, creating a high-resistivity state with a 2.9% shift under illumination. The high-resistivity state shift under laser illumination indicates defect shifts and the thermodynamic transition of ZnO defects.
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We have demonstrated a novel platform of quantum dots (QDs) core-shell conjugated graphene oxide (GO) biosensor for effective protein detection. The advantage in making core shell nanostructure allows preserving stable QDs, by improving quantum yield, and lowering the toxicity of the core. Both QDs and GO are efficient nanoparticle systems that can potentially be used for drug delivery, diagnosis, and biosensors scaffolds. However, our study indicates that the conjugation between these two nanoparticle systems makes their properties even more effective. The change in fluorescent intensity through fluorescence resonance energy transfer from quantum dots to GO produced a novel method for detection of the target and allows for the optimization of the recognition limit of Bovine serum albumin (BSA) due to efficient fluorescence resonance energy transfer as observed through time resolved relaxation spectroscopy. It is observed that the quenching of photoluminescence peak of QDs due to GO shell produced an applicable strategy and could be conveniently extended for detection of other biomolecules. We obtained significantly enhanced spectral signal through successful conjugation of GO with CdSe/CdS core shell, which can potentially be used for the detection of biomolecules with high sensitivity and selectivity. Our study underlines the efficiency of QD conjugated GO core shell in spectral detection of proteins even at very low concentration (0.25 mmol).
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We fabricated one-dimensional periodic multilayered metamaterial structures consisting of Ag and SiO2alternating layers. Optical responses, such as transmission and absorption, are consistent well within finite difference time domain (FDTD) simulations. Angle dependent real and imaginary dielectric permittivity reflection spectra demonstrate their operational capability in the visible wavelength region. This multilayer metamaterial can be converted into a photonic crystal by manipulating the thickness of SiO2 and we demonstrate that proper filling of SiO2/Ag layers the operating wavelength can be tuned to higher wavelength region. However, absolute value of transmission reduces with increasing number of multilayer pairs due to metal absorption.
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The mitochondrial DNA of trypanosomatid protozoa consists of a complex, intercatenated network of tens of maxicircles and thousands of minicircles. This structure, called kinetoplast DNA (kDNA), requires numerous proteins and multiprotein complexes for replication, segregation, and transcription. In this study, we used a proteomic approach to identify proteins that are associated with the kDNA network. We identified a novel protein encoded by Tb927.2.6100 that was present in a fraction enriched for kDNA and colocalized the protein with kDNA by fluorescence microscopy. RNA interference (RNAi) knockdown of its expression resulted in a growth defect and changes in the proportion of kinetoplasts and nuclei in the cell population. RNAi also resulted in shrinkage and loss of the kinetoplasts, loss of maxicircle and minicircle components of kDNA at similar rates, and (perhaps secondarily) loss of edited and pre-edited mRNA. These results indicate that the Tb927.2.6100 protein is essential for the maintenance of kDNA.
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ADN de Cinetoplasto/metabolismo , Proteínas Protozoarias/metabolismo , Trypanosoma brucei brucei/metabolismo , Cromatografía de Afinidad , ADN Mitocondrial/metabolismo , Reacción en Cadena de la Polimerasa , Transporte de Proteínas , Interferencia de ARN , ARN Protozoario/metabolismo , Fracciones Subcelulares/metabolismo , Trypanosoma brucei brucei/citología , Trypanosoma brucei brucei/efectos de los fármacos , Trypanosoma brucei brucei/crecimiento & desarrolloRESUMEN
This study showcases the design and development of a facile method for synthesizing trinitro-pyrazolo-triazole (TNPT) and its derivatives. The synthesized compounds are analysed using multinuclear NMR [1H, 13C, and 15N] and HRMS analyses. Furthermore, X-ray diffraction studies confirm the structure of some TNPT derivatives. Notably, compounds 8, 9, 11, and 12 exhibit good thermal stability with a decomposition threshold above 250 °C, and show a high level of insensitivity towards impact and friction [impact sensitivity (IS) is more than 25 J and friction sensitivity (FS) is above 180 N]. Compound 12, in particular, displays excellent performance characteristics [density 1.76 g cc-1 (at 298 K), a high detonation velocity (Dv = 8550 m s-1), and good thermal stability (Td = 280 °C), with high insensitivity towards impact and friction (IS = 35 J; FS = 180 N)]. The Hirshfeld surface analysis study provides further insight into the sensitivity of the TNPT derivatives.
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Mammary gland is made up of a branching network of ducts that end in alveoli. Terminally differentiated mammary epithelial cells (MECs) constitute the innermost layer of aveoli. They are milk-secreting cuboidal cells that secrete milk proteins during lactation. Little is known about the expression profile of proteins in the metabolically active MECs during lactation or their functional role in the lactation process. In the present investigation, we have reported the proteome map of MECs in lactating cows using 2DE MALDI-TOF/TOF MS and 1D-Gel-LC-MS/MS. MECs were isolated from milk using immunomagnetic beads and confirmed by RT-PCR and Western blotting. The 1D-Gel-LC-MS/MS and 2DE-MS/MS based approaches led to identification of 431 and 134 proteins, respectively, with a total of 497 unique proteins. Proteins identified in this study were clustered into functional groups using bioinformatics tools. Pathway analysis of the identified proteins revealed 28 pathways (p < 0.05) providing evidence for involvement of various proteins in lactation function. This study further provides experimental evidence for the presence of many proteins that have been predicted in annotated bovine genome. The data generated further provide a set of bovine MEC-specific proteins that will help the researchers to understand the molecular events taking place during lactation.
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Células Epiteliales/química , Glándulas Mamarias Animales/citología , Leche/citología , Proteoma/análisis , Animales , Bovinos , Femenino , Lactancia/metabolismo , Glándulas Mamarias Animales/metabolismo , Redes y Vías Metabólicas , Mapas de Interacción de Proteínas , Proteínas/análisis , Proteínas/química , Proteínas/metabolismo , Proteoma/químicaRESUMEN
The mitochondrial respiratory chain is comprised of four different protein complexes (I-IV), which are responsible for electron transport and generation of proton gradient in the mitochondrial intermembrane space. This proton gradient is then used by F0F1-ATP synthase (complex V) to produce ATP by oxidative phosphorylation. In this study, the respiratory complexes I, II, and III were affinity purified from Trypanosoma brucei procyclic form cells and their composition was determined by mass spectrometry. The results along with those that we previously reported for complexes IV and V showed that the respiratome of Trypanosoma is divergent because many of its proteins are unique to this group of organisms. The studies also identified two mitochondrial subunit proteins of respiratory complex IV that are encoded by edited RNAs. Proteomics data from analyses of complexes purified using numerous tagged component proteins in each of the five complexes were used to generate the first predicted protein-protein interaction network of the Trypanosoma brucei respiratory chain. These results provide the first comprehensive insight into the unique composition of the respiratory complexes in Trypanosoma brucei, an early diverged eukaryotic pathogen.
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Transporte de Electrón/genética , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , Mapeo de Interacción de Proteínas/métodos , Proteoma/metabolismo , Proteómica/métodos , Proteínas Protozoarias/metabolismo , Trypanosoma brucei brucei , Animales , Secuencia de Bases , Cromatografía de Afinidad , Complejo I de Transporte de Electrón/química , Complejo I de Transporte de Electrón/metabolismo , Complejo II de Transporte de Electrones/química , Complejo II de Transporte de Electrones/metabolismo , Complejo III de Transporte de Electrones/química , Complejo III de Transporte de Electrones/metabolismo , Complejo IV de Transporte de Electrones/química , Complejo IV de Transporte de Electrones/metabolismo , Humanos , Espectrometría de Masas , Mitocondrias/genética , Proteínas Mitocondriales/genética , Datos de Secuencia Molecular , Mapas de Interacción de Proteínas/genética , Proteoma/química , Proteoma/genética , Proteínas Protozoarias/genética , Edición de ARN , Trypanosoma brucei brucei/química , Trypanosoma brucei brucei/genética , Trypanosoma brucei brucei/metabolismo , Tripanosomiasis Africana/parasitologíaRESUMEN
Trypanosoma brucei is the only organism known to have evolved a multifunctional RNA polymerase I (pol I) system that is used to express the parasite's ribosomal RNAs, as well as its major cell surface antigens, namely, the variant surface glycoprotein (VSG) and procyclin, which are vital for establishing successful infections in the mammalian host and the tsetse vector, respectively. Thus far, biochemical analyses of the T. brucei RNA pol I transcription machinery have elucidated the subunit structure of the enzyme and identified the class I transcription factor A (CITFA). CITFA binds to RNA pol I promoters, and its CITFA-2 subunit was shown to be absolutely essential for RNA pol I transcription in the parasite. Tandem affinity purification (TAP) of CITFA revealed the subunits CITFA-1 to -6, which are conserved only among kinetoplastid organisms, plus the dynein light chain DYNLL1. Here, by tagging CITFA-6 instead of CITFA-2, a complex was purified that contained all known CITFA subunits, as well as a novel proline-rich protein. Functional studies carried out in vivo and in vitro, as well as a colocalization study, unequivocally demonstrated that this protein is a bona fide CITFA subunit, essential for parasite viability and indispensable for RNA pol I transcription of ribosomal gene units and the active VSG expression site in the mammalian-infective life cycle stage of the parasite. Interestingly, CITFA-7 function appears to be species specific, because expression of an RNA interference (RNAi)-resistant CITFA-7 transgene from Trypanosoma cruzi could not rescue the lethal phenotype of silencing endogenous CITFA-7.
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Subunidades de Proteína/metabolismo , Proteínas Protozoarias/metabolismo , ARN Polimerasa I/metabolismo , Factores de Transcripción/metabolismo , Transcripción Genética , Trypanosoma brucei brucei/metabolismo , Secuencia de Aminoácidos , Dineínas/metabolismo , Datos de Secuencia Molecular , Subunidades de Proteína/aislamiento & purificación , Proteínas Protozoarias/aislamiento & purificación , Factores de Transcripción/aislamiento & purificación , Trypanosoma brucei brucei/enzimología , Trypanosoma brucei brucei/genéticaRESUMEN
Tumor resection of a cancer lesion produces maxillary defects that can be easily restored with an obturator to close the defect area. Postsurgical maxillary defects predispose a patient to hypernasal speech, fluid leakage into the nasal cavity, and impaired masticatory function. Therefore, the primary aims of prosthetic rehabilitation in total and partial maxillectomy patients include: separation of oral and nasal cavities to allow adequate deglutition and articulation, possible support of orbital contents and support of soft tissue to restore mid-facial contours. A method of fabricating a simple hollow obturator for maxillectomy patients is described. The use of a relatively long-lasting light cure resin materials in making obturators allows stable, comfortable, and effective obturation. The hollow prosthesis is lightweight and sufficiently flexible to allow relatively simple placement in retentive undercut regions.
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Non-coding RNAs (ncRNAs) have emerged as key regulators of gene expression, with growing evidence implicating their involvement in cancer development and progression. The potential of ncRNAs as diagnostic and prognostic biomarkers for cancer is promising, with emphasis on their use in liquid biopsy and tissue-based diagnostics. In a nutshell, the review comprehensively summarizes the diverse classes of ncRNAs implicated in cancer, including microRNAs, long non-coding RNAs, and circular RNAs, and their functions and mechanisms of action. Furthermore, we describe the potential therapeutic applications of ncRNAs, including anti-miRNA oligonucleotides, siRNAs, and other RNA-based therapeutics in cancer treatment. However, significant challenges remain in developing effective ncRNA-based diagnostics and therapeutics, including the lack of specificity, limited understanding of mechanisms, and delivery challenges. This review also covers the current state-of-the-art non-coding RNA research technologies and bioinformatic analysis tools. Lastly, we outline future research directions in non-coding RNA research in cancer, including developing novel biomarkers, therapeutic targets, and modalities. In summary, this review provides a comprehensive understanding of non-coding RNAs in cancer and their potential clinical applications, highlighting both the opportunities and challenges in this rapidly evolving field.
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The detection of the lead heavy metal (Pb) in water is crucial in many chemical processes, as it is associated with serious health hazards. Here, we report the selective and precise colorimetric detection of Pb2+ ions in water, exploiting the aggregation and self-assembly mechanisms of glutathione (GSH)-functionalized gold nanoparticles (GNPs). The carboxyl functional groups are able to create coordination complexes with Pb2+, inducing aggregation amongst the GSH-GNPs in the presence of Pb2+ due to the chelation of the GSH ligands. The resulting aggregation amongst the GSH-GNPs in the presence of Pb2+ increases the aggregate size depending on the available Pb2+ ions, affecting the plasmonic coupling. This causes a substantial shift in the plasmon wavelength to a longer wavelength side with increasing Pb2+ concentration, resulting in a red-to-blue colorimetric or visual change, enabling the instant determination of lead content in water.
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Colorimetría , Nanopartículas del Metal , Oro , Plomo , Iones , Glutatión , Oro ColoideRESUMEN
Mitochondrial (mt) gene expression in Trypanosoma brucei entails multiple types of RNA processing, including polycistronic transcript cleavage, mRNA editing, gRNA oligouridylation, and mRNA polyadenylation, which are catalyzed by various multiprotein complexes. We examined the novel mitochondrial RNA-binding 1 (MRB1) complex that has 16 associated proteins, four of which have motifs suggesting RNA interaction. RNase treatment or the lack of kDNA in mutants resulted in lower MRB1 complex sedimentation in gradients, indicating that MRB1 complex associates with kDNA transcripts. RNAi knockdowns of expression of the Tb10.406.0050 (TbRGGm, RGG motif), Tb927.6.1680 (C2H2 zinc finger), and Tb11.02.5390 (no known motif) MRB1 proteins each inhibited in vitro growth of procyclic form parasites and resulted in cells with abnormal numbers of nuclei. Knockdown of TbRGGm, but not the other two proteins, disrupted the MRB1 complex, indicating that it, but perhaps not the other two, is required for complex assembly and/or stability. The knockdowns resulted in similar but nonidentical patterns of altered in vivo abundances of edited, pre-edited, and preprocessed mt mRNAs, but did not appreciably affect the abundances of mRNAs that do not get edited. These results indicate that MRB1 complex is critical to the processing of mt RNAs, and although its specific function is unknown, it appears essential to parasite viability.
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Proteínas Protozoarias/metabolismo , ARN Mensajero/metabolismo , ARN Protozoario/metabolismo , Trypanosoma brucei brucei/metabolismo , Animales , Técnicas de Silenciamiento del Gen , Proteínas Protozoarias/genética , Interferencia de ARN , ARN Mitocondrial , Trypanosoma brucei brucei/genéticaRESUMEN
The mitochondrial F(0)F(1) ATP synthase is an essential multi-subunit protein complex in the vast majority of eukaryotes but little is known about its composition and role in Trypanosoma brucei, an early diverged eukaryotic pathogen. We purified the F(0)F(1) ATP synthase by a combination of affinity purification, immunoprecipitation and blue-native gel electrophoresis and characterized its composition and function. We identified 22 proteins of which five are related to F(1) subunits, three to F(0) subunits, and 14 which have no obvious homology to proteins outside the kinetoplastids. RNAi silencing of expression of the F(1) alpha subunit or either of the two novel proteins showed that they are each essential for the viability of procyclic (insect stage) cells and are important for the structural integrity of the F(0)F(1)-ATP synthase complex. We also observed a dramatic decrease in ATP production by oxidative phosphorylation after silencing expression of each of these proteins while substrate phosphorylation was not severely affected. Our procyclic T. brucei cells were sensitive to the ATP synthase inhibitor oligomycin even in the presence of glucose contrary to earlier reports. Hence, the two novel proteins appear essential for the structural organization of the functional complex and regulation of mitochondrial energy generation in these organisms is more complicated than previously thought.
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ATPasas de Translocación de Protón Mitocondriales/fisiología , Trypanosoma brucei brucei/enzimología , Adenosina Trifosfato/metabolismo , Animales , Inhibidores Enzimáticos/farmacología , Técnicas de Silenciamiento del Gen , Glucosa/metabolismo , Inmunoprecipitación , ATPasas de Translocación de Protón Mitocondriales/antagonistas & inhibidores , ATPasas de Translocación de Protón Mitocondriales/química , ATPasas de Translocación de Protón Mitocondriales/genética , Oligomicinas/farmacología , Subunidades de Proteína/fisiología , Proteínas Protozoarias/genética , Proteínas Protozoarias/fisiología , Interferencia de ARN , Azida Sódica/farmacología , Trypanosoma brucei brucei/efectos de los fármacos , Trypanosoma brucei brucei/crecimiento & desarrolloRESUMEN
Mistranslation is toxic to bacterial and mammalian cells and can lead to neurodegeneration in the mouse. Mistranslation is caused by the attachment of the wrong amino acid to a specific tRNA. Many aminoacyl-tRNA synthetases have an editing activity that deacylates the mischarged amino acid before capture by the elongation factor and transport to the ribosome. For class I tRNA synthetases, the editing activity is encoded by the CP1 domain, which is distinct from the active site for aminoacylation. What is not clear is whether the enzymes also have an editing activity that is separable from CP1. A point mutation in CP1 of class I leucyl-tRNA synthetase inactivates deacylase activity and produces misacylated tRNA. In contrast, although deletion of the entire CP1 domain also disabled the deacylase activity, the deletion-bearing enzyme produced no mischarged tRNA. Further investigation showed that a second tRNA-dependent activity prevented misacylation and is intrinsic to the active site for aminoacylation.
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Escherichia coli/enzimología , Escherichia coli/genética , Leucina-ARNt Ligasa/genética , Leucina-ARNt Ligasa/metabolismo , Biosíntesis de Proteínas , Leucina-ARNt Ligasa/química , Mutación Puntual , Estructura Terciaria de Proteína , Aminoacil-ARN de Transferencia/metabolismo , Aminoacilación de ARN de TransferenciaRESUMEN
Interactions among the plant microbiome and its host are dynamic, both spatially and temporally, leading to beneficial or pathogenic relationships in the rhizosphere, phyllosphere, and endosphere. These interactions range from cellular to molecular and genomic levels, exemplified by many complementing and coevolutionary relationships. The host plants acquire many metabolic and developmental traits such as alteration in their exudation pattern, acquisition of systemic tolerance, and coordination of signaling metabolites to interact with the microbial partners including bacteria, fungi, archaea, protists, and viruses. The microbiome responds by gaining or losing its traits to various molecular signals from the host plants and the environment. Such adaptive traits in the host and microbial partners make way for their coexistence, living together on, around, or inside the plants. The beneficial plant microbiome interactions have been exploited using traditional culturable approaches by isolating microbes with target functions, clearly contributing toward the host plants' growth, fitness, and stress resilience. The new knowledge gained on the unculturable members of the plant microbiome using metagenome research has clearly indicated the predominance of particular phyla/genera with presumptive functions. Practically, the culturable approach gives beneficial microbes in hand for direct use, whereas the unculturable approach gives the perfect theoretical information about the taxonomy and metabolic potential of well-colonized major microbial groups associated with the plants. To capitalize on such beneficial, endemic, and functionally diverse microbiome, the strategic approach of concomitant use of culture-dependent and culture-independent techniques would help in designing novel "biologicals" for various crops. The designed biologicals (or bioinoculants) should ensure the community's persistence due to their genomic and functional abilities. Here, we discuss the current paradigm on plant-microbiome-induced adaptive functions for the host and the strategies for synthesizing novel bioinoculants based on functions or phylum predominance of microbial communities using culturable and unculturable approaches. The effective crop-specific inclusive microbial community bioinoculants may lead to reduction in the cost of cultivation and improvement in soil and plant health for sustainable agriculture.