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)

Defensins are a newly recognized class of small, cationic polypeptides that have in vitro microbicidal activity toward certain bacteria, fungi, and viruses. Human neutrophil granules were separated into 13 density fractions by using a high-resolution Percoll gradient centrifugation procedure, and the distribution of the three defensin polypeptides in these fractions was determined. Levels of defensins and several granule marker proteins were estimated in each fraction from relative staining intensities of bands following acid-urea and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of total acid-extractable proteins. These results were confirmed by enzyme immunoassay measurements of defensins and quantitative determinations of the typical azurophil granule components, myeloperoxidase, beta-glucuronidase, lysozyme, and elastase. The five higher density granule fractions (H1 through H5) contained fourfold higher relative amounts of defensins as compared with the eight lower density fractions (L1 through L8), accounting for approximately 50% of the total protein. In particular, fraction H5 was especially enriched in defensins but was relatively deficient in myeloperoxidase, beta-glucuronidase, lysozyme, and elastase. Ultrastructural morphology showed that fraction H5 contained the largest granules. Seventy percent of these granules exhibited electron-dense rims and electron-lucent central regions when stained with methanolic uranyl acetate-lead citrate, and 70% showed this same characteristic rim-staining pattern after limited reaction (30 minutes) for peroxidase with diaminobenzidine. These distinctively large, rim-stained granules were identified in intact, mature peripheral blood neutrophils as well as in human bone marrow promyelocytes, indicating that their synthesis occurs during early myeloid development. This unusual granule type may play a specialized role in the microbicidal functions of the neutrophil, distinct from that of typical azurophil granules.
 ...
PMID:Defensin-rich dense granules of human neutrophils. 304 Jan 55

Studies have demonstrated significant heterogeneity in neutrophil granule morphology and physical density. Using cytochemical methods to localize peroxidase and vicinal glycol containing complex carbohydrates we examined the heterogeneity of neutrophil granules from intact human neutrophil granules in 13 isolated granule density fractions, calcium ionophore A23187 treated neutrophils and neutrophils from patients with Chediak-Higashi Syndrome and Specific Granule Deficiency. At least four distinct populations of peroxidase positive granules (PPG) were identified based on peroxidase staining, vicinal glycol staining, morphology, beta-glucuronidase and defensin content, and physical density characteristics. The smallest (0.15 micron diameter) PPG was the least dense granule, had a unique peroxidase/beta-glucuronidase ratio, reacted intensely for vicinal glycols, resisted ionophore degranulation and was not consumed in giant granule formation in Chediak-Higashi Syndrome. The largest (0.3 micron average diameter) and most physically dense PPG was rich in defensins, stained weakly for vicinal glycols, and was absent in specific granule deficiency. These studies demonstrate and correlate morphologic, biochemical, functional, and pathologic differences in PPG populations.
 ...
PMID:Heterogeneity of peroxidase positive granules in normal and pathologic human neutrophils. 929 1

The plant defensin PDF1.2 has previously been shown to accumulate systemically via a salicylic acid-independent pathway in leaves of Arabidopsis upon challenge by fungal pathogens. To further investigate the signalling and transcriptional processes underlying plant defensin induction, a DNA fragment containing 1184 bp and 1232 bp upstream of the transcriptional and translational start sites, respectively, was cloned by inverse PCR. To test for promoter activity this DNA fragment was linked to the beta-glucuronidase (GUS)-encoding region of the UidA gene as a translational fusion and introduced into Arabidopsis ecotype C-24. Challenge of the transgenic plants with the fungal pathogens Alternaria brassicicola and Botrytis cinerea resulted in both local and systemic induction of the reporter gene. Wounding of the transgenic plants had no effect on GUS activity. Treatment of the transgenic plants with either jasmonates or the active oxygen generating compound paraquat strongly induced the reporter gene. In contrast, neither salicylate nor its functional analogues 2,6-dichloroisonicotinic acid and 1,2,3-benzothiodiazole-7-carbothioic acid S-methyl ester resulted in reporter gene induction. These results are consistent with the existence of a salicylic acid-independent signalling pathway, possibly involving jasmonates as regulators, that is triggered by pathogen challenge but not by wounding. The transgenic plants containing the PDF1.2-based promoter-reporter construct will provide useful tools for future genetic dissection of this novel systemic signalling pathway.
 ...
PMID:The promoter of the plant defensin gene PDF1.2 from Arabidopsis is systemically activated by fungal pathogens and responds to methyl jasmonate but not to salicylic acid. 986 13

A highly efficient system was developed for the expression of foreign genes in Chlorella ellipsoidea cells. The effect of five promoters on the expression efficiency of beta-glucuronidase (GUS) gene was evaluated by transient expression of the UidA gene. Among these promoters, Ubiquitin-omega was found to be the most efficient and was selected to drive the expression of foreign genes in Chlorella cells. A gene encoding the mature rabbit neutrophil peptide-1 (NP-1) was introduced into the cells. Integration of the gene for NP-1 into the Chlorella genome was confirmed by PCR and Southern blot analysis. In, vitro anti-microbial testes demonstrated the expression of biologically active NP-1 by the transgenic Chlorella cells.
 ...
PMID:Highly efficient expression of rabbit neutrophil peptide-1 gene in Chlorella ellipsoidea cells. 1152 11

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.
 ...
PMID:The outcomes of concentration-specific interactions between salicylate and jasmonate signaling include synergy, antagonism, and oxidative stress leading to cell death. 1637 44

SUMMARY Jasmonate and ethylene are concomitantly involved in the induction of the Arabidopsis plant defensin gene PDF1.2. To define genes in the signal transduction pathway leading to the induction of PDF1.2, we screened for mutants with induced over-expression of a beta-glucuronidase reporter, under the control of the PDF1.2 promoter. One mutant, iop1 (induced over-expressor of PDF1.2) produced small plants that showed induced over-expression of the pathogenesis-related genes PR-3, PR-4 and PR-1,2 (PDF1.2), combined with a down-regulated induction of PR-1 upon pathogen inoculation. The iop1 mutant showed enhanced resistance to a number of necrotrophic pathogens.
 ...
PMID:The Arabidopsis mutant iop1 exhibits induced over-expression of the plant defensin gene PDF1.2 and enhanced pathogen resistance. 2056 7