Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30044 (antioxidant enzyme)
 8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A cDNA corresponding to 1-Cys peroxiredoxin, an evolutionarily conserved thiol-specific antioxidant enzyme, was isolated from Xerophyta viscosa Baker, a resurrection plant indigenous to Southern Africa and belonging to the family Velloziaceae. The cDNA, designated XvPer1, contains an open reading frame that encodes a polypeptide of 219 residues with a predicted molecular weight of 24.2 kDa. The XvPer1 polypeptide shows significant sequence identity (approx. 70%) to other recently identified plant 1-Cys peroxiredoxins and relatively high levels of sequence similarity (approx. 40%) to non-plant 1-Cys peroxiredoxins. The XvPer1 cDNA contains a putative polyadenylation site. As for all 1-Cys peroxiredoxins identified to date, the amino acid sequence proposed to constitute the active site of the enzyme, PVCTTE, is highly conserved in XvPer1. It also contains a putative bipartite nuclear localization signal. Southern blot analysis revealed that there is a single copy of XvPer1 in the X. viscosa genome. All angiosperm 1-Cys peroxiredoxins described to date are seed-specific and absent in vegetative tissues even under stress conditions; therefore, XvPer1 is unique in that it is expressed in the vegetative tissues of X. viscosa. The XvPer1 transcript was absent in fully hydrated X. viscosa tissue but levels increased in tissues subjected to abiotic stresses such as dehydration, heat (42 degrees C), high light intensity (1,500 micro mol photons m(-2) s(-1)) and when treated with abscisic acid (100 micro M ABA) and sodium chloride (100 mM NaCl). Western blot analyses correlated with the patterns of expression of XvPer1 transcripts under different stress conditions. Immunofluorescence analyses revealed that XvPer1 is localized in the nucleus of dehydrated X. viscosa leaf cells. These results suggest that XvPer1 is a stress-inducible gene, which may function to protect nucleic acids within the nucleus against oxidative injury.
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PMID:A novel stress-inducible antioxidant enzyme identified from the resurrection plant Xerophyta viscosa Baker. 1224 36

Some organisms can survive exposure to extreme desiccation by entering a state of suspended animation known as anhydrobiosis. The free-living nematode Aphelenchus avenae can be induced to enter the anhydrobiotic state by exposure to a moderate reduction in relative humidity. During this preconditioning period, the nematode accumulates large amounts of the disaccharide trehalose, which is thought to be necessary, but not sufficient, for successful anhydrobiosis. To identify other adaptations that are required for anhydrobiosis, we developed a novel SL1-based mRNA differential display technique to clone genes that are upregulated by dehydration in A. avenae. Three such genes, Aav-lea-1, Aav-ahn-1, and Aav-glx-1, encode, respectively, a late embryogenesis abundant (LEA) group 3 protein, a novel protein that we named anhydrin, and the antioxidant enzyme glutaredoxin. Strikingly, the predicted LEA and anhydrin proteins are highly hydrophilic and lack significant secondary structure in the hydrated state. The dehydration-induced upregulation of Aav-lea-1 and Aav-ahn-1 was confirmed by Northern hybridization and quantitative PCR experiments. Both genes were also upregulated by an osmotic upshift, but not by cold, heat, or oxidative stress. Experiments to investigate the relationship between mRNA levels and protein expression for these genes are in progress. LEA proteins occur commonly in plants, accumulating during seed maturation and desiccation stress; the presence of a gene encoding an LEA protein in an anhydrobiotic nematode suggests that some mechanisms of coping with water loss are conserved between plants and animals.
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PMID:Dehydration-specific induction of hydrophilic protein genes in the anhydrobiotic nematode Aphelenchus avenae. 1530 29

Isoflavones in soybean were extracted in the crude form using 80% food-grade ethanol at 80 degrees C for 6 h and followed by concentration and dehydration. The soy extract contained isoflavones primarily in the forms of glucosides. In vitro antioxidant activities of the soy extract containing 20-500 ppm isoflavones were conducted using a Rancimat method. The results showed that soy isoflavone extract had strong in vitro antioxidant activity. There was a dose-dependent response for the in vitro antioxidant activity at the lower concentrations but not at the higher concentrations. In vivo antioxidant property was determined by measuring the antioxidant enzymes, superoxide dismutase, and catalase in various organs of rats that were fed with diets containing partially oxidized oil and various levels of isoflavones for up to 24 weeks. Neither short-term (8 weeks) feeding nor low isoflavone content (50 ppm) induced changes in superoxide dismutase or catalase activities in rats. Only diets containing high isoflavone contents (150 and 250 ppm) showed obvious elevated enzymatic levels in various organs. In addition, a laboratory-prepared tofu containing approximately 50 ppm isoflavones had better effects than the soy extract with the 250 ppm isoflavone group, which indicated that molecules other than isoflavones may have a synergistic effect on in vivo antioxidant enzyme inductions of tofu.
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PMID:Antioxidant properties of soybean isoflavone extract and tofu in vitro and in vivo. 1576 77

With cDNA from Phellodendron amurense seedlings treated with drought stress as tester and cDNA from this plant in normal growth as driver, we construct cDNA subtracted library using suppression subtractive hybridization (SSH). In the library, the rate of recombination was 95%, the size of inserts was 300-800 bp. Two hundred and sixty-five new genes were obtained by DNA sequencing 816 positive clones picked randomly, and partitioned to 16 classes after nucleotide Blast and BlastX homological analysis against NT, NR, SWISSPROT, KEGG database. Forty-four drought stress associated genes, such as heat shock protein cognate 70, dehydration responsive protein 22, universal stress protein, metallothionein II, late embryogenesis abundant protein, were obtained, which made 16.6% of the overall genes. These genes included osmotic regulator, signal component regulatory protein and antioxidant enzyme. The research had established a basis for cloning stress resistance genes and further studying genes expression in P. amurense seedlings under drought stress.
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PMID:[Construction and analysis of subtractive cDNA library of Phellodendron amurense under drought stress]. 1846

The relationships among desiccation sensitivities of Antiaris toxicaria seeds and axes, changes in activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR) and dehydroascorbate reductase, (DHAR), production rate of superoxide radical (.O(2) (-)), and the contents of hydrogen peroxide (H(2)O(2)) and thiobarbituric acid (TBA)-reactive substance were studied. Desiccation tolerance of seeds and axes decreased with dehydration. Desiccation tolerance of axes was higher than that of seeds, and that of epicotyls was higher than radicles. Activities of SOD, CAT and DHAR of seeds increased during the initial phase of dehydration, and then decreased with further dehydration, whereas activities of APX and GR decreased with dehydration. These five enzyme activities of axes, however, increased during the initial phase of dehydration, and then decreased with further dehydration. The rate of superoxide radical production, and the contents of H(2)O(2) and TBA-reactive products of seeds and axes gradually increased with dehydration. These results show that the A. toxicaria seed is a typical recalcitrant seed. Loss of desiccation tolerance in seeds and axes was correlated with the increase in .O(2) (-) production rate, content of H(2)O(2) and TBA-reactive products, and the decline of antioxidant enzyme activities of seeds and axes.
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PMID:Possible involvement of reactive oxygen species scavenging enzymes in desiccation sensitivity of Antiaris toxicaria seeds and axes. 1909 73

Metallothioneins (MTs) are small, cysteine-rich, metal-binding proteins that may be involved in metal homeostasis and detoxification in both plants and animals. OsMT1a, encoding a type 1 metallothionein, was isolated via suppression subtractive hybridization from Brazilian upland rice (Oryza sativa L. cv. Iapar 9). Expression analysis revealed that OsMT1a predominantly expressed in the roots, and was induced by dehydration. Interestingly, the OsMT1a expression was also induced specifically by Zn(2+) treatment. Both transgenic plants and yeasts harboring OsMT1a accumulated more Zn(2+) than wild type controls, suggesting OsMT1a is most likely to be involved in zinc homeostasis. Transgenic rice plants overexpressing OsMT1a demonstrated enhanced tolerance to drought. The examination of antioxidant enzyme activities demonstrated that catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) were significantly elevated in transgenic plants. Furthermore, the transcripts of several Zn(2+)-induced CCCH zinc finger transcription factors accumulated in OsMT1a transgenic plants, suggesting that OsMT1a not only participates directly in ROS scavenging pathway but also regulates expression of the zinc finger transcription factors via the alteration of Zn(2+) homeostasis, which leads to improved plant stress tolerance.
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PMID:OsMT1a, a type 1 metallothionein, plays the pivotal role in zinc homeostasis and drought tolerance in rice. 1922 38

Reaumuria soongorica (Pall.) Maxim. is a short woody shrub widely found in semi-arid areas of China, and can survive severe environmental stresses. To understand its potential signaling transduction pathway in stress tolerance, we investigated the participation of mitogen-activated protein kinases (MAPKs) as possible mediators of abiotic stresses. A novel MAP kinase cDNA (RsMPK2) that encodes a 374 amino acid protein was isolated from R. soongorica. RsMPK2 belongs to the C1 subgroup, which is still functionally uncharacterized compared to groups A and B; and contains all 11 of the conserved MAPK subdomains and the TEY phosphorylation motif. RsMPK2 is expressed in vegetative (root, stem, leaf and callus) and reproductive (flower) organs. The transcripts of RsMPK2 were rapidly accumulated at high levels when R. soongorica was subjected to dehydration, salinity conditions and treatment with abscisic acid or hydrogen peroxide. Growth analysis of Escherichia coli (srl::Tn10) cells transformed with pPROEXHT-RsMPK2 showed that the expression products of RsMPK2 do not act as an osmoprotectant. But, the inhibition of RsMPK2 expression by the inhibitor U0126 induced a decrease of antioxidant enzyme activity under stresses, indicating that RsMPK2 is involved in the regulation of the antioxidant defense system in the response to stress signaling.
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PMID:Molecular characterization of RsMPK2, a C1 subgroup mitogen-activated protein kinase in the desert plant Reaumuria soongorica. 2083 58

Using the mRNA differential display combined with 5' rapid amplification of cDNA ends (RACE) technique, an early nodulin-like protein gene (BcBCP1) (accession no. AY243047.1) was isolated from drought-treated Boea crassifolia leaves. The full-length cDNA of BcBCP1 consists of 844 bp nucleotides and has an open reading frame of 606 bp, encoding a putative polypeptide of 201 amino acids with a predicted molecular mass of 22 kDa and a pI of 5.13. The putative protein precursor contains four sequence domains, including a 27 amino acid hydrophobic N-terminal transit peptide, a 100 amino acid phytocyanin-homologous globular domain, a 51 amino acid hydroxyproline-rich cell wall structural protein domain, and a 22 amino acid hydrophobic extension domain. Sequence alignment defined the encoded protein as an early nodulin-like protein, and the absence of key ligands implies that it is unlikely to bind copper. BcBCP1 expression was strongly induced by dehydration, salinity and abscisic acid (ABA), slightly induced by moderate heat shock, and weakly inhibited by low temperature, methyl jasmonic acid (MeJA), and a low concentration of salicylic acid (SA). Overexpression of BcBCP1 in tobacco under the control of CaMV 35S promoter enhanced tolerance to osmotic stress, as indicated by the less impaired growth, less damaged membrane integrity and lower lipid peroxidation levels after osmotic stress. Transgenic tobacco lines overexpressing BcBCP1 showed higher photosynthetic rates, higher antioxidant enzyme activities and higher cytosyl ascorbic peroxidase transcription levels than non-transgenic tobacco plants, both under normal conditions and under osmotic stress.
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PMID:A phytocyanin-related early nodulin-like gene, BcBCP1, cloned from Boea crassifolia enhances osmotic tolerance in transgenic tobacco. 2145 74

Desiccation-tolerance in vegetative tissues of angiosperms has a polyphyletic origin and could be due to 1) appropriation of the seed-specific program of gene expression that protects orthodox seeds against desiccation, and/or 2) a sustainable version of the abiotic stress response. We tested these hypotheses by comparing molecular and physiological data from the development of orthodox seeds, the response of desiccation-sensitive plants to abiotic stress, and the response of desiccation-tolerant plants to extreme water loss. Analysis of publicly-available gene expression data of 35 LEA proteins and 68 anti-oxidant enzymes in the desiccation-sensitive Arabidopsis thaliana identified 13 LEAs and 4 anti-oxidants exclusively expressed in seeds. Two (a LEA6 and 1-cys-peroxiredoxin) are not expressed in vegetative tissues in A. thaliana, but have orthologues that are specifically activated in desiccating leaves of Xerophyta humilis. A comparison of antioxidant enzyme activity in two desiccation-sensitive species of Eragrostis with the desiccation-tolerant E. nindensis showed equivalent responses upon initial dehydration, but activity was retained at low water content in E. nindensis only. We propose that these antioxidants are housekeeping enzymes and that they are protected from damage in the desiccation-tolerant species. Sucrose is considered an important protectant against desiccation in orthodox seeds, and we show that sucrose accumulates in drying leaves of E. nindensis, but not in the desiccation-sensitive Eragrostis species. The activation of "seed-specific" desiccation protection mechanisms (sucrose accumulation and expression of LEA6 and 1-cys-peroxiredoxin genes) in the vegetative tissues of desiccation-tolerant plants points towards acquisition of desiccation tolerance from seeds.
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PMID:The signature of seeds in resurrection plants: a molecular and physiological comparison of desiccation tolerance in seeds and vegetative tissues. 2167 29

The mitogen-activated protein kinase (MAPK) cascade plays pivotal roles in diverse signalling pathways related to plant development and stress responses. In this study, the cloning and functional characterization of a group-I MAPK gene, PtrMAPK, in Poncirus trifoliata (L.) Raf are reported. PtrMAPK contains 11 highly conserved kinase domains and a phosphorylation motif (TEY), and is localized in the nucleus of transformed onion epidermal cells. The PtrMAPK transcript level was increased by dehydration and cold, but was unaffected by salt. Transgenic overexpression of PtrMAPK in tobacco confers dehydration and drought tolerance. The transgenic plants exhibited better water status, less reactive oxygen species (ROS) generation, and higher levels of antioxidant enzyme activity and metabolites than the wild type. Interestingly, the stress tolerance capacity of the transgenic plants was compromised by inhibitors of antioxidant enzymes. In addition, overexpression of PtrMAPK enhanced the expression of ROS-related and stress-responsive genes under normal or drought conditions. Taken together, these data demonstrate that PtrMAPK acts as a positive regulator in dehydration/drought stress responses by either regulating ROS homeostasis through activation of the cellular antioxidant systems or modulating transcriptional levels of a variety of stress-associated genes.
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PMID:Cloning and molecular characterization of a mitogen-activated protein kinase gene from Poncirus trifoliata whose ectopic expression confers dehydration/drought tolerance in transgenic tobacco. 2177 84


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