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Plant immunity is activated upon pathogen perception and often affects growth and yield when it is constitutively active. How plants fine-tune immune homeostasis in their natural habitats remains elusive. Here, we discover a conserved immune suppression network in cereals that orchestrates immune homeostasis, centering on a Ca2+-sensor, RESISTANCE OF RICE TO DISEASES1 (ROD1). ROD1 promotes reactive oxygen species (ROS) scavenging by stimulating catalase activity, and its protein stability is regulated by ubiquitination. ROD1 disruption confers resistance to multiple pathogens, whereas a natural ROD1 allele prevalent in indica rice with agroecology-specific distribution enhances resistance without yield penalty. The fungal effector AvrPiz-t structurally mimics ROD1 and activates the same ROS-scavenging cascade to suppress host immunity and promote virulence. We thus reveal a molecular framework adopted by both host and pathogen that integrates Ca2+ sensing and ROS homeostasis to suppress plant immunity, suggesting a principle for breeding disease-resistant, high-yield crops.
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Calcio/metabolismo , Depuradores de Radicales Libres/metabolismo , Proteínas Fúngicas/metabolismo , Oryza/inmunología , Inmunidad de la Planta , Proteínas de Plantas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Sistemas CRISPR-Cas/genética , Membrana Celular/metabolismo , Resistencia a la Enfermedad/genética , Modelos Biológicos , Oryza/genética , Enfermedades de las Plantas/inmunología , Proteínas de Plantas/genética , Unión Proteica , Estabilidad Proteica , Reproducción , Especificidad de la Especie , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación , Zea mays/inmunologíaRESUMEN
Leaf rust, caused by Puccinia triticina Erikss. (Pt), is a serious disease threatening wheat (Triticum aestivum L.) production worldwide. Hydrogen peroxide (H2O2) triggered by Pt infection in resistant wheat cultivars cause oxidative damage directly to biomolecules or is activated by calcium signaling and mediates the hypersensitive response. Calmodulin-binding transcriptional activator 4 (TaCAMTA4) has been reported to negatively regulate wheat resistance to Pt. In this study, we found that TaCAMTA4 was induced by Pt race 165 in its compatible host harboring the Pt resistant locus Lr26, TcLr26, and silencing of TaCAMTA4 increased local H2O2 accumulation and Pt resistance. Subcellular localization and autoactivation tests revealed that TaCAMTA4 is a nucleus-localized transcriptional activator. Furthermore, four DNA motifs recognized by TaCAMTA4 were identified by transcription factor-centered Y1H. Through analyzing the transcriptome database, four gene clusters were identified, each containing a different DNA motif on each promoter. Among them, the expression of catalase 1 (TaCAT1) with motif-1 was highly induced in the compatible interaction and was decreased when TaCAMTA4 was silenced. The results of EMSA, ChIP-qPCR, and RT-qPCR further showed that TaCAMTA4 directly bound motif-1 in the TaCAT1 promoter. Furthermore, silencing of TaCAT1 resulted in enhanced resistance to Pt and increased local H2O2 accumulation in wheat, which is consistent with that of TaCAMTA4. Since CAMTAs are Ca2+ sensors and catalases catalyze the decomposition of H2O2, we hypothesize that Ca2+ regulates the plant immune networks that are controlled by H2O2 and implicate a potential mechanism for Pt to suppress resistance by inducing the expression of the TaCAMTA4-TaCAT1 module, which consequently enhances H2O2 scavenging and attenuates H2O2-dependent resistance.
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Overexpression of vesicular stomatitis virus G protein (VSV-G) elevates the secretion of EVs known as gectosomes, which contain VSV-G. Such vesicles can be engineered to deliver therapeutic macromolecules. We investigated viral glycoproteins from several viruses for their potential in gectosome production and intracellular cargo delivery. Expression of the viral glycoprotein (viral glycoprotein from the Chandipura virus [CNV-G]) from the human neurotropic pathogen Chandipura virus in 293T cells significantly augments the production of CNV-G-containing gectosomes. In comparison with VSV-G gectosomes, CNV-G gectosomes exhibit heightened selectivity toward specific cell types, including primary cells and tumor cell lines. Consistent with the differential tropism between CNV-G and VSV-G gectosomes, cellular entry of CNV-G gectosome is independent of the Low-density lipoprotein receptor, which is essential for VSV-G entry, and shows varying sensitivity to pharmacological modulators. CNV-G gectosomes efficiently deliver diverse intracellular cargos for genomic modification or responses to stimuli in vitro and in the brain of mice in vivo utilizing a split GFP and chemical-induced dimerization system. Pharmacokinetics and biodistribution analyses support CNV-G gectosomes as a versatile platform for delivering macromolecular therapeutics intracellularly.
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Vesiculovirus , Animales , Humanos , Ratones , Vesiculovirus/genética , Vesiculovirus/metabolismo , Vesículas Extracelulares/metabolismo , Proteínas del Envoltorio Viral/metabolismo , Proteínas del Envoltorio Viral/genética , Glicoproteínas/metabolismo , Glicoproteínas/genética , Células HEK293 , Proteínas Virales/metabolismo , Proteínas Virales/genética , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Sistemas de Liberación de Medicamentos/métodos , Línea Celular TumoralRESUMEN
The application of integrated systems biology to the field of structural biology is a promising new direction, although it is still in the infant stages of development. Here we report the use of single particle cryo-EM to identify multiple proteins from three enriched heterogeneous fractions prepared from human liver mitochondrial lysate. We simultaneously identify and solve high-resolution structures of nine essential mitochondrial enzymes with key metabolic functions, including fatty acid catabolism, reactive oxidative species clearance, and amino acid metabolism. Our methodology also identified multiple distinct members of the acyl-CoA dehydrogenase family. This work highlights the potential of cryo-EM to explore tissue proteomics at the atomic level.
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Mitocondrias , Proteómica , Humanos , Mitocondrias/metabolismo , Hígado/metabolismo , Oxidación-ReducciónRESUMEN
Catalase is a major antioxidant enzyme located in plant peroxisomes that catalyzes the decomposition of H2O2. Based on our previous transcriptomic (RNA-Seq) and proteomic (iTRAQ) data at different stages of pepper (Capsicum annuum L.) fruit ripening and after exposure to nitric oxide (NO) enriched atmosphere, a broad analysis has allowed us to characterize the functioning of this enzyme. Three genes were identified, and their expression was differentially modulated during ripening and by NO gas treatment. A dissimilar behavior was observed in the protein expression of the encoded protein catalases (CaCat1-CaCat3). Total catalase activity was down-regulated by 50% in ripe (red) fruits concerning immature green fruits. This was corroborated by non-denaturing polyacrylamide gel electrophoresis, where only a single catalase isozyme was identified. In vitro analyses of the recombinant CaCat3 protein exposed to peroxynitrite (ONOO-) confirmed, by immunoblot assay, that catalase underwent a nitration process. Mass spectrometric analysis identified that Tyr348 and Tyr360 were nitrated by ONOO-, occurring near the active center of catalase. The data indicate the complex regulation at gene and protein levels of catalase during the ripening of pepper fruits, with activity significantly down-regulated in ripe fruits. Nitration seems to play a key role in this down-regulation, favoring an increase in H2O2 content during ripening. This pattern can be reversed by the exogenous NO application. While plant catalases are generally reported to be tetrameric, the analysis of the protein structure supports that pepper catalase has a favored quaternary homodimer nature. Taken together, data show that pepper catalase is down-regulated during fruit ripening, becoming a target of tyrosine nitration, which provokes its inhibition.
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Capsicum , Catalasa , Frutas , Óxido Nítrico , Proteínas de Plantas , Capsicum/genética , Capsicum/crecimiento & desarrollo , Capsicum/enzimología , Capsicum/metabolismo , Catalasa/metabolismo , Catalasa/genética , Frutas/crecimiento & desarrollo , Frutas/genética , Frutas/metabolismo , Frutas/enzimología , Frutas/efectos de los fármacos , Óxido Nítrico/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Peróxido de Hidrógeno/metabolismo , Ácido Peroxinitroso/metabolismoRESUMEN
Catalases are essential enzymes for removal of hydrogen peroxide, enabling aerobic and anaerobic metabolism in an oxygenated atmosphere. Monofunctional heme catalases, catalase-peroxidases, and manganese catalases, evolved independently more than two billion years ago, constituting a classic example of convergent evolution. Herein, the diversity of catalase sequences is analyzed through sequence similarity networks, providing the context for sequence distribution of major catalase families, and showing that many divergent catalase families remain to be experimentally studied.
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Catalasa , Evolución Molecular , Catalasa/química , Catalasa/genética , Catalasa/metabolismo , Humanos , Animales , Peróxido de Hidrógeno/metabolismo , Peróxido de Hidrógeno/química , Hemo/química , Hemo/metabolismoRESUMEN
Intrauterine growth restriction (IUGR) is associated with increased risk of cardiometabolic disease later in life and has been shown to affect female and male offspring differently, but the mechanisms remain unclear. The purpose of this study was to identify proteomic differences and metabolic risk markers in IUGR male and female neonates when compared to appropriate for gestational age (AGA) babies that will provide a better understanding of IUGR pathogenesis and its associated risks. Our results revealed alterations in IUGR cord plasma proteomes with most of the differentially abundant proteins implicated in peroxisome pathways. This effect was evident in females but not in males. Furthermore, we observed that catalase activity, a peroxisomal enzyme, was significantly increased in females (p < 0.05) but unchanged in males. Finally, we identified risk proteins associated with obesity, type-2 diabetes, and glucose intolerance such as EGF containing fibulin extracellular matrix protein 1 (EFEMP1), proprotein convertase subtilisin/kexin type 9 (PCSK9) and transforming growth factor beta receptor 3 (TGFBR3) proteins unique to females while coagulation factor IX (C9) and retinol binding protein 4 (RBP4) are unique in males. In conclusion, IUGR may display sexual dimorphism which may be associated with differences in lifelong risk for cardiometabolic disease between males and females.
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Enfermedades Cardiovasculares , Retardo del Crecimiento Fetal , Recién Nacido , Lactante , Humanos , Masculino , Femenino , Retardo del Crecimiento Fetal/etiología , Retardo del Crecimiento Fetal/metabolismo , Retardo del Crecimiento Fetal/patología , Proproteína Convertasa 9/metabolismo , Proteómica , Proteínas Plasmáticas de Unión al Retinol , Proteínas de la Matriz Extracelular/metabolismoRESUMEN
Photorespiration is an essential metabolic mechanism associated with photosynthesis; however, little is known about the photorespiratory pathway of conifer gymnosperms. Metabolite analyses of the leaves of 27 tree species showed that the mean glycerate content in conifer leaves was lower than that in angiosperm leaves. We performed experiments where [13 C]-serine was fed to detached shoots of a conifer (Cryptomeria japonica), via the transpiration stream, and compared the labeling patterns of photorespiratory metabolites with those of an angiosperm tree (Populus nigra), because glycerate is produced from serine via hydroxypyruvate in peroxisomes. In P. nigra, hydroxypyruvate, glycerate and glycine were labeled with 13 C, whereas in C. japonica, glycolate and a non-canonical photorespiratory metabolite, formate, were also labeled, suggesting that an H2 O2 -mediated non-enzymatic decarboxylation (NED) reaction occurs in C. japonica. We analyzed changes in the metabolite contents of leaves kept in the dark and leaves exposed to illuminated photorespiration-promoting conditions: a positive relationship between formate and serine levels in C. japonica implied that the active C1 -metabolism pathway synthesizes serine from formate. Leaf gas exchange analyses revealed that CO2 produced through NED was recaptured by chloroplasts. Database analysis of the peroxisomal targeting signal motifs of an H2 O2 -scavenging enzyme, catalase, derived from various species, including nine coniferous species, as well as analyses of peroxisomal fractions isolated from C. japonica and P. nigra leaves indicated that conifer peroxisomes had less catalase activity. These results suggest that NED and the subsequent C1 metabolism are involved in the photorespiratory pathway of conifer leaves, where peroxisomes have intrinsically low catalase activity.
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Magnoliopsida , Tracheophyta , Peroxisomas/metabolismo , Tracheophyta/metabolismo , Catalasa/metabolismo , Fotosíntesis , Magnoliopsida/metabolismo , Hojas de la Planta/metabolismo , Serina/metabolismoRESUMEN
Fatty acid oxidation (FAO) releases the energy stored in fat to maintain basic biological processes. Dehydrogenation is a major way to oxidize fatty acids, which needs NAD+ to accept the released H+ from fatty acids and form NADH, which increases the ratio of NADH/NAD+ and consequently inhibits FAO leading to the deposition of fat in the liver, which is termed fatty liver or steatosis. Consumption of alcohol (ethanol) initiates simple steatosis that progresses to alcoholic steatohepatitis, which constitutes a spectrum of liver disorders called alcohol-associated liver disease (ALD). ALD is linked to ethanol metabolism. Ethanol is metabolized by alcohol dehydrogenase (ADH), microsomal ethanol oxidation system (MEOS), mainly cytochrome P450 2E1 (CYP2E1), and catalase. ADH also requires NAD+ to accept the released H+ from ethanol. Thus, ethanol metabolism by ADH leads to increased ratio of NADH/NAD+, which inhibits FAO and induces steatosis. CYP2E1 directly consumes reducing equivalent NADPH to oxidize ethanol, which generates reactive oxygen species (ROS) that lead to cellular injury. Catalase is mainly present in peroxisomes, where very long-chain fatty acids and branched-chain fatty acids are oxidized, and the resultant short-chain fatty acids will be further oxidized in mitochondria. Peroxisomal FAO generates hydrogen peroxide (H2O2), which is locally decomposed by catalase. When ethanol is present, catalase uses H2O2 to oxidize ethanol. In this review, we introduce FAO (including α-, ß-, and ω-oxidation) and ethanol metabolism (by ADH, CYP2E1, and catalase) followed by the interaction between FAO and ethanol metabolism in the liver and its pathophysiological significance.
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Hígado Graso , Hepatopatías Alcohólicas , Humanos , Catalasa , NAD , Citocromo P-450 CYP2E1 , Peróxido de Hidrógeno , Etanol , Ácidos GrasosRESUMEN
BACKGROUND: This study examines the impact of titanium dioxide nanoparticles (TiO2NPs) on gene expression associated with menthol biosynthesis and selected biochemical parameters in peppermint plants (Mentha piperita L.). Menthol, the active ingredient in peppermint, is synthesized through various pathways involving key genes like geranyl diphosphate synthase, menthone reductase, and menthofuran synthase. Seedlings were treated with different concentrations of TiO2NPs (50, 100, 200, and 300 ppm) via foliar spray. After three weeks of treatment, leaf samples were gathered and kept at -70 °C for analysis. RESULTS: According to our findings, there was a significant elevation (P ≤ 0.05) in proline content at concentrations of 200 and 300 ppm in comparison with the control. Specifically, the highest proline level was registered at 200 ppm, reaching 259.64 ± 33.33 µg/g FW. Additionally, hydrogen peroxide and malondialdehyde content exhibited a decreasing trend following nanoparticle treatments. Catalase activity was notably affected by varying TiO2NP concentrations, with a significant decrease observed at 200 and 300 ppm compared to the control (P ≤ 0.05). Conversely, at 100 ppm, catalase activity significantly increased (11.035 ± 1.12 units/mg of protein/min). Guaiacol peroxidase activity decreased across all nanoparticle concentrations. Furthermore, RT-qPCR analysis indicated increased expression of the studied genes at 300 ppm concentration. CONCLUSIONS: Hence, it can be inferred that at the transcript level, this nanoparticle exhibited efficacy in influencing the biosynthetic pathway of menthol.
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Regulación de la Expresión Génica de las Plantas , Mentha piperita , Mentol , Nanopartículas , Titanio , Titanio/farmacología , Mentha piperita/efectos de los fármacos , Mentha piperita/metabolismo , Mentha piperita/genética , Mentol/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Hojas de la Planta/metabolismo , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Nanopartículas del Metal , Genes de Plantas , Peróxido de Hidrógeno/metabolismoRESUMEN
The harsh environment of diabetic wounds, including bacterial infection and wound hypoxia, is not conducive to wound healing. Herein, an enzyme-like photocatalytic octahedral Rh/Ag2MoO4 is developed to manage diabetic-infected wounds. The introduction of Rh nanoparticles with catalase-like catalytic activity can enhance the photothermal conversion and photocatalytic performance of Rh/Ag2MoO4 by improving near-infrared absorbance and promoting the separation of electron-hole pairs, respectively. Rh/Ag2MoO4 can effectively eliminate pathogens through a combination of photothermal and photocatalytic antibacterial therapy. After bacteria inactivation, Rh/Ag2MoO4 can catalyze hydrogen peroxide to produce oxygen to alleviate the hypoxic environment of diabetic wounds. The in vivo treatment effect demonstrated the excellent therapeutic performance of Rh/Ag2MoO4 on diabetic infected wounds by removing infectious pathogens and relieving oxygen deficiency, confirming the potential application of Rh/Ag2MoO4 in the treatment of diabetic infected wounds.
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Crohn's disease (CD) is a chronic relapsing inflammatory disorder in which defective apoptosis of mucosal T cells is postulated to produce sustained inflammation and reactive oxygen species accumulation. Whether CD T cells are intrinsically resistant to apoptosis or whether this resistance is acquired at the intestinal site needs to be clarified, as the cellular mechanisms modulate the impaired apoptosis in these cells. Here, we analysed peripheral blood T cells from patients naïve to specific CD treatment at the onset and from healthy controls. Non-activated freshly purified lymphocytes were cultured and submitted to in vitro protocols for activation (CD3/CD28 antibodies) and apoptosis (Fas antibody). Cells were analysed by flow cytometry. Caspases (3, 8, and 9) and catalase activity were measured; protein levels of bax, Bcl-2, and NF-kB were detected by western blotting, and cytokines by Luminex-based assays. The results showed that CD4 T cells from CD patients are less prone to apoptosis before they can migrate to the intestinal mucosa. Caspase-9, FasR, sIL-2Rα, IL-17A, IFNγ, IL-6, TNF-α, and IL-10 were shown to be significantly different in CD but not for the rest of the analysed biological elements. Catalase activity was significantly reduced in CD T cells, which was confirmed in ex vivo experiments in which catalase inhibition in T cells from healthy controls triggered apoptosis inhibition in a dose-dependent manner. In conclusion, apoptosis inhibition of CD T cells is a feature of these cells before they can migrate to the intestinal mucosa. Noteworthy, the impaired apoptosis of T cells can be directly influenced by catalase inhibition.
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Apoptosis , Catalasa , Enfermedad de Crohn , Humanos , Enfermedad de Crohn/inmunología , Enfermedad de Crohn/patología , Catalasa/metabolismo , Adulto , Femenino , Masculino , Citocinas/metabolismo , Persona de Mediana Edad , Mucosa Intestinal/inmunología , Mucosa Intestinal/patología , Células Cultivadas , Linfocitos T CD4-Positivos/inmunología , Activación de Linfocitos/inmunología , Adulto Joven , Linfocitos T/inmunología , Caspasas/metabolismoRESUMEN
A plethora of gene regulatory mechanisms with eccentric attributes in Deinoccocus radiodurans confer it to possess a distinctive ability to survive under ionizing radiation. Among the many regulatory processes, small RNA (sRNA)-mediated regulation of gene expression is prevalent in bacteria but barely investigated in D. radiodurans. In the current study, we identified a novel sRNA, DrsS, through RNA-seq analysis in D. radiodurans cells while exposed to ionizing radiation. Initial sequence analysis for promoter identification revealed that drsS is potentially co-transcribed with sodA and dr_1280 from a single operon. Elimination of the drsS allele in D. radiodurans chromosome resulted in an impaired growth phenotype under γ-radiation. DrsS has also been found to be upregulated under oxidative and genotoxic stresses. Deletion of the drsS gene resulted in the depletion of intracellular concentration of both Mn2+ and Fe2+ by ~70% and 40%, respectively, with a concomitant increase in carbonylation of intracellular protein. Complementation of drsS gene in ΔdrsS cells helped revert its intracellular Mn2+ and Fe2+ concentration and alleviated carbonylation of intracellular proteins. Cells with deleted drsS gene exhibited higher sensitivity to oxidative stress than wild-type cells. Extrachromosomally expressed drsS in ΔdrsS cells retrieved its oxidative stress resistance properties by catalase-mediated detoxification of reactive oxygen species (ROS). In vitro binding assays indicated that DsrS directly interacts with the coding region of the katA transcript, thus possibly protecting it from cellular endonucleases in vivo. This study identified a novel small RNA DrsS and investigated its function under oxidative stress in D. radiodurans. IMPORTANCE: Deinococcus radiodurans possesses an idiosyncratic quality to survive under extreme ionizing radiation and, thus, has evolved with diverse mechanisms which promote the mending of intracellular damages caused by ionizing radiation. As sRNAs play a pivotal role in modulating gene expression to adapt to altered conditions and have been delineated to participate in almost all physiological processes, understanding the regulatory mechanism of sRNAs will unearth many pathways that lead to radioresistance in D. radiodurans. In that direction, DrsS has been identified to be a γ-radiation-induced sRNA, which is also induced by oxidative and genotoxic stresses. DrsS appeared to activate catalase under oxidative stress and detoxify intracellular ROS. This sRNA has also been shown to balance intracellular Mn(II) and Fe concentrations protecting intracellular proteins from carbonylation. This novel mechanism of DrsS identified in D. radiodurans adds substantially to our knowledge of how this bacterium exploits sRNA for its survival under stresses.
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Proteínas Bacterianas , Deinococcus , Regulación Bacteriana de la Expresión Génica , ARN Bacteriano , Especies Reactivas de Oxígeno , Deinococcus/genética , Deinococcus/efectos de la radiación , Deinococcus/metabolismo , Especies Reactivas de Oxígeno/metabolismo , ARN Bacteriano/genética , ARN Bacteriano/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Radiación Ionizante , ARN Pequeño no Traducido/genética , ARN Pequeño no Traducido/metabolismo , Estrés Oxidativo , Rayos gammaRESUMEN
Catalase (CAT) is the main reactive oxygen species (ROS)-scavenging enzyme in plants and insects. However, it remains elusive whether and how insect saliva CAT suppresses ROS-mediated plant defense, thereby promoting initial virus transmission by insect vectors. Here, we investigated how leafhopper Recilia dorsalis catalase (RdCAT) was secreted from insect salivary glands into rice phloem, and how it was perceived by rice chaperone NO CATALASE ACTIVITY1 (OsNCA1) to scavenge excessive H2O2 during insect-to-plant virus transmission. We found that the interaction of OsNCA1 with RdCAT activated its enzymatic activity to decompose H2O2 in rice plants during leafhopper feeding. However, initial insect feeding did not significantly change rice CATs transcripts. Knockout of OsNCA1 in transgenic lines decreased leafhopper feeding-activated CAT activity and caused higher H2O2 accumulation. A devastating rice reovirus activated RdCAT expression and promoted the cosecretion of virions and RdCAT into leafhopper salivary cavities and ultimately into the phloem. Virus-mediated increase of RdCAT secretion suppressed excessive H2O2, thereby promoting host attractiveness to insect vectors and initial virus transmission. Our findings provide insights into how insect saliva CAT is secreted and perceived by plant chaperones to suppress the early H2O2 burst during insect feeding, thereby facilitating viral transmission.
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Catalasa , Hemípteros , Peróxido de Hidrógeno , Insectos Vectores , Oryza , Saliva , Animales , Peróxido de Hidrógeno/metabolismo , Hemípteros/virología , Hemípteros/fisiología , Saliva/virología , Saliva/enzimología , Catalasa/metabolismo , Catalasa/genética , Insectos Vectores/virología , Oryza/virología , Oryza/genética , Oryza/enzimología , Reoviridae/fisiología , Enfermedades de las Plantas/virología , Floema/virologíaRESUMEN
Cassava is one of the most important tuber crops that is used for food, starch and bio-energy. However, cassava is susceptible to a number of diseases, especially cassava bacterial blight (CBB). Nitric oxide (NO) and hydrogen peroxide (H2O2) regulate plant growth and development, as well as stress responses. However, no direct relationships between the enzymes involved in the metabolic enzymes that produce and process these key signaling molecules has been demonstrated. Here, we provide evidence for the interaction between the nitrate reductase 2 (MeNR2) and catalase 1 (MeCAT1) proteins in vitro and in vivo, using yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays, respectively. MeNR2 is a positive regulator and MeCAT1 is a negative regulator of CBB resistance. MeNR2 was localized in the nucleus, cell membrane and peroxisome, while MeCAT1 was localized in the peroxisomes. The interactions between MeNR2 and MeCAT1 also had effects of their respective enzyme activities. Taken together, the data presented here suggested that there is coordination between H2O2 and NO signaling in cassava disease resistance, through the interactions between MeCAT1 and MeNR2.
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Cyanobacteria have been recognized for their advantageous impact on plant growth and development. The application of certain techniques has the potential to enhance various aspects of plant development, including growth, yield, proximate content (such as protein and carbohydrate levels), as well as the ability to withstand abiotic stresses such as herbicide exposure. The current investigation focused on examining the influence of bioactive compounds derived from the cyanobacterium Neowestiellopsis persica strain A1387 on enhancing the antioxidant and anyimicrobial activity of wheat plants in their defense against the plant pathogenic Sunn pest. The findings of the study indicate that the levels of H2O2 and GPx in wheat plants that were infected with aphids were significantly elevated compared to the treatments where aphids and cyanobacteria extract were present. The confirmation of these results was achieved through the utilization of confocal and fluorescent microscope tests, respectively. Furthermore, the findings indicated that the constituents of the cyanobacterial extract augmented the plant's capacity to withstand stress by enhancing its defense mechanisms. In a broader context, the utilization of cyanobacterial extract demonstrated the ability to regulate the generation and impact of oxygen (O2) and hydrogen peroxide (H2O2), while concurrently enhancing the functionality of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) enzymes within wheat plants. This facilitation enabled the plants to effectively manage oxidative stress. Moreover, the findings of the antibacterial activity assessment conducted on the extract derived from cyanobacteria demonstrated notable susceptibility. The bacteria that exhibited the highest sensitivity to the extract of cyanobacterium Neowestiellopsis persica strain A1387 were staphylococcus aureus and pseudomonas aeruginosa. Conversely, salmonella typhi demonstrated the greatest resistance to the aforementioned extract. The potential impact of cyanobacteria extract on the antioxidative response of wheat plants to sunn pest infestation represents a novel contribution to the existing body of knowledge on the interaction between wheat plants and aphids.
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Antiinfecciosos , Cianobacterias , Plaguicidas , Antioxidantes/farmacología , Antioxidantes/metabolismo , Triticum/microbiología , Plaguicidas/metabolismo , Peróxido de Hidrógeno/metabolismo , Estrés Oxidativo , Superóxido Dismutasa/metabolismo , Oxígeno/metabolismo , Cianobacterias/metabolismo , Antiinfecciosos/metabolismo , Extractos Vegetales/farmacología , Extractos Vegetales/metabolismoRESUMEN
Antioxidants exert a paradoxical influence on cancer prevention. The latest explanation for this paradox is the different target sites of antioxidants. However, it remains unclear how mitochondria-targeted antioxidants trigger specific p53-dependent pathways in malignant transformation models. Our study revealed that overexpression of mitochondria-targeted catalase (mCAT) instigated such malignant transformation via mouse double minute 2 homolog (MDM2) -mediated p53 degradation. In mouse epithelial JB6 Cl41 cells, the stable expression of mCAT resulted in MDM2-mediated p53 degradation, unlike in catalase-overexpressed Cl41 cells. Further, we demonstrated that mCAT overexpression upregulated ubiquitin-specific protease 28 (USP28) expression, which in turn stabilized c-Jun protein levels. This alteration initiated the activation of the miR-200b promoter transcription activity and a subsequent increase in miR-200b expression. Furthermore, elevated miR-200b levels then promoted its binding to the 3'-untranslated region of protein phosphatase 2A catalytic subunit (PP2A-C) α-isoform mRNA, consequently resulting in PP2A-C protein downregulation. This cascade of events ultimately contributed to increased MDM2 phosphorylation and p53 protein degradation. Thus, the mCAT overexpression triggers MDM2/p53-dependent malignant transformation through USP28/miR-200b/PP2A-Cα pathway, which may provide a new information for understanding mitochondria-targeted antioxidants facilitate the progression to the tumorigenic state.
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Catalasa , Transformación Celular Neoplásica , Regulación hacia Abajo , MicroARNs , Mitocondrias , Proteína Fosfatasa 2 , Estabilidad Proteica , Proteínas Proto-Oncogénicas c-mdm2 , Proteína p53 Supresora de Tumor , Ubiquitina Tiolesterasa , Proteína p53 Supresora de Tumor/metabolismo , Proteína p53 Supresora de Tumor/genética , MicroARNs/metabolismo , MicroARNs/genética , Animales , Ratones , Mitocondrias/metabolismo , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteínas Proto-Oncogénicas c-mdm2/genética , Ubiquitina Tiolesterasa/metabolismo , Ubiquitina Tiolesterasa/genética , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/genética , Catalasa/metabolismo , Catalasa/genética , Proteína Fosfatasa 2/metabolismo , Proteína Fosfatasa 2/genética , Humanos , Línea Celular , Transducción de Señal , Regulación Neoplásica de la Expresión GénicaRESUMEN
Ribosome assembly defects result in ribosomopathies, primarily caused by inadequate protein synthesis and induced oxidative stress. This study aimed to investigate the link between deleting one ribosomal protein gene (RPG) paralog and oxidative stress response. Our results indicated that RPG mutants exhibited higher oxidant sensitivity than the wild type (WT). The concentrations of H2O2 were increased in the RPG mutants. Catalase and superoxide dismutase (SOD) activities were generally higher at the stationary phase, with catalase showing particularly elevated activity in the RPG mutants. While both catalase genes, CTT1 and CTA1, consistently exhibited higher transcription in RPG mutants, Ctt1 primarily contributed to the increased catalase activity. Stress-response transcription factors Msn2, Msn4, and Hog1 played a role in regulating these processes. Previous studies have demonstrated that H2O2 can cleave 25S rRNA via the Fenton reaction, enhancing ribosomes' ability to translate mRNAs associated with oxidative stress-related genes. The cleavage of 25S rRNA was consistently more pronounced, and the translation efficiency of CTT1 and CTA1 mRNAs was altered in RPG mutants. Our results provide evidence that the mutations in RPGs increase H2O2 levels in vivo and elevate catalase expression through both transcriptional and translational controls.
Asunto(s)
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Catalasa/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas Ribosómicas/genética , Proteínas Ribosómicas/metabolismo , Peróxido de Hidrógeno/farmacología , Estrés Oxidativo , Superóxido Dismutasa-1/metabolismo , MutaciónRESUMEN
BACKGROUND: Calcium is a ubiquitous intracellular messenger that regulates the expression of various genes involved in cell proliferation, differentiation, and motility. The involvement of calcium in diverse metabolic pathways has been suggested. However, the effect of calcium in peroxisomes, which are involved in fatty acid oxidation and scavenges the result reactive oxygen species (ROS), remains elusive. In addition, impaired peroxisomal ROS inhibit the mammalian target of rapamycin complex 1 (mTORC1) and promote autophagy. Under stress, autophagy serves as a protective mechanism to avoid cell death. In response to oxidative stress, lysosomal calcium mediates transcription factor EB (TFEB) activation. However, the impact of calcium on peroxisome function and the mechanisms governing cellular homeostasis to prevent diseases caused by calcium deficiency are currently unknown. METHODS: To investigate the significance of calcium in peroxisomes and their roles in preserving cellular homeostasis, we established an in-vitro scenario of calcium depletion. RESULTS: This study demonstrated that calcium deficiency reduces catalase activity, resulting in increased ROS accumulation in peroxisomes. This, in turn, inhibits mTORC1 and induces pexophagy through TFEB activation. However, treatment with the antioxidant N-acetyl-l-cysteine (NAC) and the autophagy inhibitor chloroquine impeded the nuclear translocation of TFEB and attenuated peroxisome degradation. CONCLUSIONS: Collectively, our study revealed that ROS-mediated TFEB activation triggers pexophagy during calcium deficiency, primarily because of attenuated catalase activity. We posit that calcium plays a significant role in the proper functioning of peroxisomes, critical for fatty-acid oxidation and ROS scavenging in maintaining cellular homeostasis. These findings have important implications for signaling mechanisms in various pathologies, including Zellweger's syndrome and ageing.
Asunto(s)
Calcio , Macroautofagia , Especies Reactivas de Oxígeno/metabolismo , Calcio/metabolismo , Catalasa/metabolismo , Estrés Oxidativo , Autofagia/genética , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismoRESUMEN
BACKGROUND: This study examined whether the severity of mitral valve stenosis (MVS) is associated with oxidative stress (OS) markers in the blood, and other hematological and clinicodemographic parameters.MethodsâandâResults: This prospective study was conducted between March and May 2022. Seventy-five patients with newly diagnosed MVS (25 mild, 25 moderate, 25 severe) were included. Mild, moderate, and severe MVS was defined as MV area >2, 1.5-2, and <1.5 cm2, respectively. Various OS markers and laboratory parameters were determined in venous blood samples. For predictive analyses, 2 different analyses were performed to detect patients with severe MVS and those with moderate or severe (moderate/severe) MVS. Age (P=0.388) and sex (P=0.372) distribution were similar in the 3 groups. Multiple logistic regression analysis revealed that a high white blood cell (WBC) count (P=0.023) and high malondialdehyde (P=0.010), superoxide dismutase (SOD; P=0.008), and advanced oxidation protein products (AOPP; P=0.007) levels were independently associated with severe MVS. A low platelet count (P=0.030) and high malondialdehyde (P=0.018), SOD (P=0.008), and AOPP (P=0.001) levels were independently associated with having moderate/severe MVS. The best discriminatory factors for severe MVS were SOD (cut-off >315.5 ng/mL) and glutathione (cut-off >4.7 µmol/L). CONCLUSIONS: MVS severity seems to be affected by oxidant markers (malondialdehyde and AOPP), antioxidant enzymes (SOD), and inflammation-related cells (WBC and platelets). Future studies are needed to examine these relationships in larger populations.