Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The catalase gene katA of Lactobacillus sakei LTH677 was cloned and expressed in Escherichia coli UM2, Lactobacillus casei LK1, and Lactobacillus curvatus LTH1432. The last host is a catalase-deficient plasmid-cured derivative of a starter organism used in meat fermentation. The regulation of katA expression was found to be the same in L. sakei LTH677 and the recombinant strains. The addition of H2O2 to anaerobic cultures, as well as a switch to aerobic conditions, resulted in a strong increase in KatA activity. The expression was investigated in more detail with L. sakei LTH677 and L. curvatus LTH4002. The recombinant strain LTH4002 did not accumulate H2O2 under glucose-limited aerobic conditions and remained viable in the stationary phase. Under inductive conditions, the katA-specific mRNA and the apoenzyme were synthesized de novo. Deletion derivatives of the katA promoter were produced, and the regulatory response was investigated by fusion to the beta-glucuronidase reporter gene gusA and expression in L. sakei LTH677. The fact that gene expression was subject to induction was confirmed at the level of transcription and protein synthesis. A small putative regulatory sequence of at least 25 bp was identified located upstream of the -35 site. Competition experiments performed with L. sakei LTH677 harboring the fusion constructs consisting of the katA promoter and gusA revealed that an activator protein is involved in the transcriptional induction of katA.
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PMID:Oxygen-dependent regulation of the expression of the catalase gene katA of Lactobacillus sakei LTH677. 954 73

The differentiation of chloroplasts into chromoplasts involves a series of biochemical changes that culminate with the intense accumulation of long chain chromophore carotenoids such as lycopene, rhodoxanthin, astaxanthin, anhydroeschsoltzxanthin, capsanthin, and capsorubin. The signal pathways mediating these transformations are unknown. Chromoplast carotenoids are known to accumulate in green tissues experiencing stress conditions, and studies indicate that they provide efficient protection against oxidative stress. We tested the role of reactive oxygen species (ROS) as regulators of chromoplast carotenoid biosynthesis in vivo. The addition of ROS progenitors, such as menadione, tert-butylhydroperoxide, or paraquat and prooxidants such as diamide or buthionine sulfoximine to green pericarp discs of pepper fruits rapidly and dramatically induce the simultaneous expression of multiple carotenogenic gene mRNAS that give rise to capsanthin. Similarly, down-regulation of catalase by amitrole induces expression of carotenogenic gene mRNAs leading to the synthesis of capsanthin in excised green pericarp discs. ROS signals from plastids and mitochondria also contribute significantly to this process. Analysis of the capsanthin-capsorubin synthase promoter in combination with a beta-glucuronidase reporter gene reveals strong activation in transformed pepper protoplasts challenged with the above ROS. Collectively these data demonstrate that ROS act as a novel class of second messengers that mediate intense carotenoid synthesis during chromoplast differentiation.
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PMID:Induction and control of chromoplast-specific carotenoid genes by oxidative stress. 980 38

Aesculin-hydrolyzing, catalase-negative, gram-positive cocci isolated from subclinical intramammary infections in dairy cows were identified to species level using growth characteristics and biochemical activity. The results indicated that the aesculin-hydrolyzing cocci associated with this type of infection are a very heterogenic group. S. uberis strains, including inulin- or beta-glucuronidase-negative isolates, accounted for only about one-third of the collection, and Enterococcus faecalis strains for one-fifth. Other species of some importance included (in descending order of isolation frequency) Aerococcus viridans, Streptococcus pluranimalium, Lactococcus garvieae, Streptococcus bovis and Streptococcus gallolyticus.
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PMID:Identification of aesculin-hydrolyzing streptococci, lactococci, aerococci and enterococci from subclinical intramammary infections in dairy cows. 1059

Portal hypertensive gastropathy is associated with a broad spectrum of gastric mucosal damage inspite of decreased gastric acid secretion, suggestive of compromised endogenous protective mechanisms. To determine the mechanisms of damage in portal hypertensive gastropathy we measured lipid peroxidation, glutathione, antioxidant and lysosomal enzymes in gastric mucosal homogenates from male Wistar rats with elevated intrasplenic pulp pressure, eighteen days after common bile duct ligation. Thiobarbituric acid-reactive substances and lysosomal enzymes (beta-glucuronidase and acid phosphatase) were increased in the common bile duct ligated group as compared to the sham-operated group. The levels of antioxidant defense enzymes, superoxide dismutase, glutathione peroxidase, catalase and glutathione were decreased as compared to the sham-operated controls. Pre-operative vitamin E administration decreased mucosal lipid peroxidation increased the levels of antioxidant defense enzymes and lowered the lysosomal enzymes. The plasma vitamin E levels in this group were lower when compared to animals receiving it post-operatively. In conclusion, free radical and lysosomal enzyme mediated damage may play a role in portal hypertensive gastropathy.
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PMID:Gastropathy and defense mechanisms in common bile duct ligated portal hypertensive rats. 1072 35

alpha-1,4-Linked oligogalacturonides (OGs) inhibit auxin-regulated transcriptional activation of a rolB-beta-glucuronidase (GUS) gene fusion in tobacco (Nicotiana tabacum) leaf explants (D. Bellincampi, M. Cardarelli, D. Zaghi, G. Serino, G. Salvi, C. Gatz, F. Cervone, M. M. Altamura, P. Costantino, G. De Lorenzo [1996] Plant Cell 8: 477-487). In this paper we show that inhibition by OGs is very rapid, with a short lag time, and takes place even after rolB promoter activation has initiated. OGs also induce a transient and catalase-sensitive accumulation of H(2)O(2) in the leaf explant culture medium. OGs with a degree of polymerization from 12 to 15 are required for both the inhibition of the auxin-induced rolB-driven accumulation of GUS and the induction of H(2)O(2) accumulation(.) However, OG concentration for half-maximal induction of H(2)O(2) accumulation is approximately 3-fold higher than that for half-maximal inhibition of rolB promoter activity. The inhibition of rolB promoter activity is not influenced by the addition of catalase or superoxide dismutase, suggesting that H(2)O(2) and superoxide are not involved in this effect. A fungal oligo-beta-glucan elicitor induces extracellular H(2)O(2) accumulation at comparable or higher levels than those observed with OGs, but does not prevent the auxin-induced accumulation of GUS. We conclude that H(2)O(2) produced upon treatment with OGs is not involved in the inhibition of the auxin-induced expression of the rolB gene.
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PMID:Extracellular H(2)O(2) induced by oligogalacturonides is not involved in the inhibition of the auxin-regulated rolB gene expression in tobacco leaf explants. 1075 34

The activation sequence-1 (as-1)-like element found in the promoter of some glutathione S-transferase (GST) genes, has been previously described as a salicylic acid (SA)- and auxin-responsive element. In this paper, we tested the hypothesis that the activating effect of SA on the as-1 element is mediated by oxidative species. Supporting this hypothesis, our results show that the antioxidants dimethylthiourea (DMTU) and 3-t-butyl-4-hydroxy-anizole (BHA) inhibit the SA-induced transcription of genes controlled by as-1 elements in tobacco (Nicotiana tabacum) plants [i.e. GNT35 gene coding for a GST and (as-1)(4)/beta-glucuronidase (GUS) reporter transgene]. DMTU and BHA also inhibit SA-activated as-1-binding activity in nuclear extracts. Further support for the hypothesis that the as-1 element is activated by oxidative species comes from our result showing that light potentiates the SA-induced activation of the as-1 element. Furthermore, methyl viologen, a known oxidative stress inducer in plants, also activates the as-1 element. Increasing H(2)O(2) levels by incubation with H(2)O(2) or with the catalase inhibitor 3-amino-1,2,5-triazole does not activate the (as-1)(4)/GUS gene. On the contrary, 3-amino-1,2,5-triazole inhibits the activating effect of SA on the (as-1)(4)/GUS gene. These results suggest that oxidative species other than H(2)O(2) mediate the activation of the as-1 element by SA. Our results also suggest that even though the as-1 binding activity is stimulated by oxidative species, this is not sufficient for the transactivation of genes controlled by this element. The complex interplay between SA and reactive oxygen species in the transcriptional activation of defense genes is discussed.
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PMID:The as-1 promoter element is an oxidative stress-responsive element and salicylic acid activates it via oxidative species. 1242 16

Adriamycin, which is widely used in the treatment of various neoplastic conditions, exerts toxic effects in many organs. The present study was designed to investigate the effect of lipoic acid upon adriamycin induced peroxidative damages in rat kidney. The increase in peroxidated lipids on adriamycin administration was accompanied by alterations in the antioxidant defense systems. The extent of nephrotoxicity induced by adriamycin was evident from the decreased activities of the enzymes gamma-glutamyl transferase and beta-glucuronidase in the rat renal tissues. The study was carried out with adult male albino rats of Wistar strain, which comprised of one control and three experimental groups. Group I rats served as controls. Group II rats received adriamycin (1 mg kg(-1) body wt day(-1)) intravenously through the tail vein. Group III rats were given lipoic acid (35 mg kg(-1) body wt day(-1)) intraperitoneally. Group IV rats were given lipoic acid 24 h before the administration of adriamycin. Rats subjected to adriamycin administration showed a decline in the thiol capacity of the cell accompanied by high malondialdehyde levels along with lowered activities of catalase, superoxide dismutase, glutathione peroxidase and glutathione metabolizing enzymes (glutathione reductase, glucose-6-phosphate dehydrogenase, glutathione-S-transferase). Lipoic acid pretreatment also restored the activities of gamma-glutamyl transferase and beta-glucuronidase nearly to control levels thereby suggesting nephroprotection. The study has highlighted the beneficial effects of lipoic acid pretreatment in reversing the damages caused by adriamycin and thereby bringing about an improvement in the oxidative stress parameters.
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PMID:Protective effect of lipoic acid on adriamycin induced lipid peroxidation in rat kidney. 1284 25

THE COMPOSITION OF ISOLATED NUCLEI AND CELL PREPARATIONS FROM TISSUES OF CALF, BEEF, HORSE, AND FOWL WAS STUDIED WITH RESPECT TO THE FOLLOWING COMPONENTS: 1. Liver and kidney arginase, catalase, and uricase; pancreatic lipase and amylase; cardiac muscle myoglobin; erythrocyte hemoglobin; intestinal alkaline phospharase. These are referred to as "special" components in view of their characteristically restricted distribution reflecting the differentiated nature of the tissues in question. 2. Esterase, beta-glucuronidase, alkaline and nucleotide phosphatases, adenosine deaminase, guanase, and nucleoside phosphorylase. These are enzymes of general distribution. The differences in nuclear composition noted with respect to the "special" components, together with the broad variability in nuclear activity found for enzymes of general distribution, led to the conclusion that nuclei are differentiated structures. The following distribution was observed: 1. "Special" components: Hemoglobin was found to be present in fowl and goose erythrocyte nuclei, but myoglobin was entirely absent from heart muscle nuclei; of the special enzymes listed, only catalase and arginase appeared to be concentrated in some of the nuclei. There was no significant nuclear concentration of lipase, amylase, uricase, or alkaline phosphatase. No simple relationship was found between the concentration of a special enzyme in a tissue and its activity in the corresponding nuclei. For example, arginase activity, which is high in mammalian liver and in fowl kidney, was found in liver, not kidney, nuclei. Similarly, catalase activity was demonstrated only in mammalian liver nuclei, although, in mammals, both liver and kidney are rich sources of this enzyme. 2. Enzymes of general distribution fell into three classes: (a) Those present in low concentrations, if at all, in the nuclei-alkaline phosphatase, the nucleotide phosphatases) and beta-glucuronidase. (b) Those present in nuclei in varying concentrations-esterase. (c) Those present in high proportions in most nuclei-adenosine deaminase, nucleoside phosphorylase, and guanase. The exceptionally low nuclear activity of intestinal mucosa with respect to these enzymes was discussed in relation to physiological considerations. The response of nuclei to changes in physiological state was demonstrated by experiments on starvation. The outstanding aspect of this response was a change in nuclear enzymatic activity opposing that observed in the cytoplasm. A comparison of fetal and adult mucosa cells led to the following tentative interpretation of the observed intracellular enzyme distribution: In cells tending to moribundity, as in those subjected to starvation, relative nuclear enzymatic activity falls. The occurrence of special enzymes in nuclei was considered in terms of differentiation, and the high nuclear concentration of the nucleoside-specific enzymes was interpreted in terms of general nuclear metabolic activity.
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PMID:Some enzymes of isolated nuclei. 1489 35

The present study aimed at assessing the role of histone H1 in activating macrophages. Histone H1, injected intraperitoneally at a dose of 1 mg/kg body weight as multiple regimens weekly, significantly increased the number of peritoneal macrophages post 21 days of injection. The oxidative and non-oxidative activation of peritoneal macrophages by histone H1 was assessed. For the assessment of oxidative activation the levels of superoxide radical and nitric oxide radical were assessed. The oxidative activation was evident from release of significantly high levels of superoxide and nitric oxide radicals liberated by macrophages of animals treated with histone H1 (P < 0.001) than in untreated animals. In addition, the higher activities of superoxide dismutase indicated protective effect of histone H1, to keep away the macrophages from noxious effects of superoxide. The catalase activity was decreased significantly in macrophages of histone H1 treated animals. The levels of reduced glutathione were significantly (P < 0.001) lowered in treated animals, whereas the levels of lipid peroxides generated were non-significant. The non-oxidative activation was assessed from the activities of lysosomal enzymes released and also from cytolysis of NO-insensitive L929 cells. The activities of lysosomal enzymes-acid phosphatase and beta-glucuronidase released were significantly high in treated animals than in untreated animals (P < 0.001). Histone H1 stimulated the cytolysis of macrophages in L929 cells than in untreated animals. These results suggest that histone H1 stimulates macrophages by oxidative and non-oxidative mechanisms, which favor its future therapeutic prospects.
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PMID:Oxidative and non-oxidative activation of murine peritoneal macrophages by histone H1. 1523 95

Salicylic acid (SA) has been proposed to antagonize jasmonic acid (JA) biosynthesis and signaling. We report, however, that in salicylate hydroxylase-expressing tobacco (Nicotiana tabacum) plants, where SA levels were reduced, JA levels were not elevated during a hypersensitive response elicited by Pseudomonas syringae pv phaseolicola. The effects of cotreatment with various concentrations of SA and JA were assessed in tobacco and Arabidopsis (Arabidopsis thaliana). These suggested that there was a transient synergistic enhancement in the expression of genes associated with either JA (PDF1.2 [defensin] and Thi1.2 [thionin]) or SA (PR1 [PR1a-beta-glucuronidase in tobacco]) signaling when both signals were applied at low (typically 10-100 microm) concentrations. Antagonism was observed at more prolonged treatment times or at higher concentrations. Similar results were also observed when adding the JA precursor, alpha-linolenic acid with SA. Synergic effects on gene expression and plant stress were NPR1- and COI1-dependent, SA- and JA-signaling components, respectively. Electrolyte leakage and Evans blue staining indicated that application of higher concentrations of SA + JA induced plant stress or death and elicited the generation of apoplastic reactive oxygen species. This was indicated by enhancement of hydrogen peroxide-responsive AoPR10-beta-glucuronidase expression, suppression of plant stress/death using catalase, and direct hydrogen peroxide measurements. Our data suggests that the outcomes of JA-SA interactions could be tailored to pathogen/pest attack by the relative concentration of each hormone.
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PMID:The outcomes of concentration-specific interactions between salicylate and jasmonate signaling include synergy, antagonism, and oxidative stress leading to cell death. 1637 44


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