Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The fission yeast cells that contained the cloned glutathione synthetase (GS) gene showed 1.4-fold higher glutathione (GSH) content and 1.9-fold higher GS activity than the cells without the cloned GS gene. Interestingly, gamma-glutamylcysteine synthetase activity increased 2.1-fold in the S. pombe cells that contained the cloned GS gene. The S. pombe cells that harbored the multicopy-number plasmid pRGS49 (containing the cloned GS gene) showed a higher level of survival on solid media with cadmium chloride (1 mM) or mercuric chloride (10 microM) than the cells that harbored the YEp357R vector. The 506 bp upstream sequence from the translational initiation point and N-terminal 8 amino acid-coding region were fused into the promoterless beta-galactosidase gene of the shuttle vector YEp367R to generate the fusion plasmid pUGS39. Synthesis of beta-galactosidase from the fusion plasmid pUGS39 was significantly enhanced by cadmium chloride and NO-generating S-nitroso-N-acetylpenicillamine (SNAP) and sodium nitroprusside (SN). It was also induced by L-buthionine-(S,R)-sulfoximine, a specific inhibitor of gamma-glutamylcysteine synthetase (GCS). We also found that the expression of the S. pombe GS gene is regulated by the Atf1-Spc1-Wis1 signal pathway.
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PMID:Regulation of the gene encoding glutathione synthetase from the fission yeast. 1278 90

A multivariate model is proposed relating short-term biomarker measurements in Daphnia magna to chronic effects (21-d exposure) occurring at the population level (time to death, mean brood size, mean total young per female, intrinsic rate of natural increase, net reproductive rate, and growth). The results of the short-term exposure (48 h-96 h) to eight model toxicants (cadmium, chromium, mercury, tributyl tin, linear alkylsulfonic acid, sodium pentachlorophenolate, lindane, and 2,4-dichlorophenoxyacetic acid) on the following biomarkers were used for the multivariate model: digestive enzymes (amylase, cellulase, beta-galactosidase, trypsin, and esterase), enzymes of the intermediary metabolism (glycogen phosphorylase, glucose-6-phosphate dehydrogenase, pyruvate kinase, lactate dehydrogenase, and isocitrate dehydrogenase), cellular energy allocation (CEA) (protein, carbohydrate, and lipid content and electron transport activity), and DNA damage and antioxidative stress activity. Using partial least squares to latent structures (PLS), a two-component model was obtained with R2 of 0.68 and a Q2 value of 0.60 based on the combined analysis of a limited number of the 48- and 96-h biomarker responses. For the individual population-level responses, the R2 values varied from 0.66 to 0.77 and the Q2 values from 0.52 to 0.69. Energy-related biomarkers (cellular energy allocation, lipid contents, anaerobic metabolic activity--pyruvate kinase, and lactate dehydrogenase), combined with parameters related to oxidative stress (catalase) and DNA damage measured after 48 and 96 h of exposure, were able to predict long-term effects at higher levels of biological organization.
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PMID:A multivariate biomarker-based model predicting population-level responses of Daphnia magna. 1295 51

Long-term exposure to cadmium (Cd) induces perturbation of kidney proximal tubular epithelial cells. Mitochondrial dysfunction in renal cortical cells may contribute to the pathogenesis of Cd-induced nephropathy. In this study, we examined the accumulation of mitochondrial DNA (mtDNA) with a large deletion and cellular senescence in the renal cortex. Wistar rats at 8 weeks of age were intraperitoneally injected with 1 mL of 1 mM CdCl(2) or saline, 3 times/week for 5, 20, 40, or 80 weeks. Mitochondrial Cd content in the renal cortex was quantified by atomic absorption analysis. Cytochrome c oxidase (CCO) and senescence-associated beta-galactosidase (SA-beta-gal) activity were determined in renal cortex by enzyme-histochemistry. mtDNA in total DNA extracted from the renal cortex was amplified by PCR, and mtDNA deletions, including 4,834-bp (nt8118-nt12937) deletion, were determined and semiquantified. After 40 weeks of Cd injection, Cd levels in the renal cortex reached a saturation level, and 30% of the level of the whole-cell fraction was found in the mitochondria. CCO activity in the renal cortex, which was predominantly found in proximal tubular cells, decreased after 40 weeks of Cd exposure. Expression of SA-beta-gal was detected primarily in the proximal tubular cells and significantly increased after 80 weeks of Cd exposure. After 40 weeks of study, accumulation of 4,834-bp deletion in mtDNA was evident in both groups of rats; however, the amount of the deletion was significantly greater in Cd-treated rats than in control rats. Our results indicate that long-term Cd exposure induced a post-regenerative state of proximal tubular cells, which accelerated accumulation of 4,834-bp mtDNA deletions in the renal cortex, suggesting that Cd may be a senescence acceleration factor for kidney proximal tubular epithelial cells, which results in Cd-induced nephropathy.
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PMID:Cadmium-induced nephropathy in rats is mediated by expression of senescence-associated beta-galactosidase and accumulation of mitochondrial DNA deletion. 1512 10

Work in cadmium (Cd) smelter and smoking cigarettes damages teeth and oral mucosa which are protected by tissue and salivary glycoconjugates: glycoproteins, glycolipids, and proteoglycans. We worked out a rat model imitating human "environmental" and "occupational" exposure to cadmium using 5 mg Cd and 50 mg Cd/l in drinking water, respectively. In submandibulary glands of exposed to Cd rats, we found the time and dose dependent accumulation of Cd and simultanous decrease in activity of beta-N-acetylhexosaminidase (HEX). In homogenates of submandibulary glands of control rats, beta-N-acetylhexosaminidase showed the highest activity. The activities of alpha-mannosidase and beta-galactosidase were very low. None of these exoglycosidases were inhibited by Cd even at 44 mM concentration.
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PMID:Activity of lysosomal exoglycosidases in submandibular glands of rats intoxicated by cadmium at doses related to human chronic environmental and occupational exposures. 1544 43

Glutaredoxin (Grx), also known as thioltransferase (TTase), is an enzyme that catalyzes the reduction of a variety of disulfide compounds, including protein disulfides, in the presence of reduced glutathione. A second gene encoding Grx (Grx2) was cloned from the chromosomal DNA of the fission yeast Schizosaccharomyces pombe. The determined DNA sequence contains 1645 bp which is able to encode a polypeptide of 110 amino acids with a molecular mass of 12.2 kDa. The genomic DNA consists of 4 exons and 3 introns. The isolated gene was found to produce functional glutaredoxin that could accelerate the growth of the fission yeast, and is highly expressed at the mid- and late exponential phases. Aluminum, cadmium and hydrogen peroxide marginally enhanced the synthesis of beta-galactosidase from the Grx2-lacZ fusion gene. Shifts to lower concentrations (0.2, 0.4 or 0.8%) of D-glucose significantly enhanced the synthesis of beta-galactosidase from the Grx2-lacZ fusion gene. And shifts to sucrose (0.2, 0.4, 0.8 or 1.6%) as a sole carbon source markedly enhanced the synthesis of beta-galactosidase from the Grx2-lacZ fusion gene, the degree of which was inversely dependent on concentration. However, nonfermentable carbon sources reduced the expression of the Grx2 gene due to their growth arrest. The transcription factor Pap1 is not involved in the basal expression and induction of the Grx2 gene. The Grx2 protein was subcellularly localized in the nucleus of the yeast cells. Our results indicate that the Grx2 protein, located in the nucleus, is linked with the yeast growth, and that the gene is regulated by carbon sources.
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PMID:Carbon source-dependent regulation of a second gene encoding glutaredoxin from the fission yeast Schizosaccharomyces pombe. 1586 6

Glutaredoxin (Grx) is a small, heat-stable protein acting as a multi-functional glutathione-dependent disulfide oxidoreductase. In this work, a gene encoding the monothiol glutaredoxin Grx4 was cloned from the genomic DNA of the fission yeast Schizosaccharomyces pombe. The determined DNA sequence carries 1706 bp, which is able to encode the putative 244 amino acid sequence of Grx with 27 099 Da. It does not contain an intron, and the sequence CGFS is found in the active site. Grx activity was increased 1.46-fold in S. pombe cells harboring the cloned Grx4 gene, indicating that the Grx4 gene is in vivo functioning. Although aluminum, cadmium, and hydrogen peroxide marginally enhanced the synthesis of beta-galactosidase from the Grx4-lacZ fusion gene, NO-generating sodium nitroprusside (0.5 mmol/L and 1.0 mmol/L) and potassium chloride (0.2 mol/L and 0.5 mol/L) significantly enhanced it. The Grx4 mRNA level was also enhanced after the treatment with sodium nitroprusside and potassium chloride. The synthesis of beta-galactosidase from the Grx4-lacZ gene was increased by fermentable carbon sources, such as glucose (lower than 2%) and sucrose, but not by nonfermentable carbon sources such as acetate and ethanol. The basal expression of the S. pombe Grx4 gene did not depend on the presence of Pap1. These results imply that the S. pombe monothiol Grx4 gene is genuinely functional and regulated by a variety of stresses.
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PMID:Stress-dependent regulation of a monothiol glutaredoxin gene from Schizosaccharomyces pombe. 1617 11

Glutaredoxins (Grxs) are thioloxidoreductases which are required for maintaining thiol/disulfide equilibrium in living cells. The Grx3 gene, which encodes one of the three monothiol Grxs in the fission yeast Schizosaccharomyces pombe, was characterized, and its transcriptional regulation studied. Genomic DNA encoding Grx3 was isolated by PCR, and a plasmid pTT3 carrying this DNA was produced. The DNA sequence has 1,267 bp, which would encode a monothiol Grx of 166 amino acids with a molecular mass of 18.3 kDa. The putative protein has 27% homology with Grx5, and contains many hydrophobic amino acid residues in its N-terminal region. S. pombe cells harboring pTT3 had increased Grx activity and enhanced survival on minimal medium plates containing aluminum (5 mM), BSO (0.05 mM), menadione (0.01 mM) or cadmium (0.2 mM). The 568 bp upstream region of Grx3 was fused into the promoterless beta-galactosidase gene of the shuttle vector YEp367R to generate fusion plasmid pMJS10. Potassium chloride (KCl) and metals including aluminum and cadmium enhanced the synthesis of beta-galactosidase from the fusion gene. The synthesis of beta-galactosidase was also enhanced, in a Pap1-dependent manner, by fermentable carbon sources such as glucose (at low concentrations) and sucrose, but not by non-fermentable carbon sources such as ethanol and acetate. Grx3 mRNA increased in response to treatment with BSO. These observations indicate that S. pombe Grx3 is involved in the response to stress, and is regulated by stress.
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PMID:Characterization and regulation of the gene encoding monothiol glutaredoxin 3 in the fission yeast Schizosaccharomyces pombe. 1625 44

In the current work, regulation of the pap1(+) gene was investigated by the use of the pap1(+)-lacZ fusion gene and semi-quantitative reverse transcriptase-PCR. The synthesis of beta-galactosidase from the pap1(+)-lacZ fusion gene was significantly enhanced by nitric oxide (NO)-generating sodium nitroprusside (SNP) and nitrogen starvation. However, the induction by SNP and nitrogen starvation was observed to be much less in the Pap1p-negative cells harboring the fusion gene. Exogenous NO was more effectively scavenged in the Pap1p-positive cells than in the Pap1p-negative cells. Oxidative stress such as superoxide anion, hydrogen peroxide and cadmium could not give rise to an effect on the synthesis of beta-galactosidase from the fusion gene. The pap1(+) mRNA level was elevated in the wild-type cells by SNP and nitrogen starvation. Catalase activity, a major enzyme positively regulated by Pap1p, was significantly increased only in the Pap1p-positive cells by SNP. In brief, it is demonstrated that transcription of the Schizosaccharomyces pombe pap1(+) gene is positively regulated by nitrosative and nutritional stress in a Pap1p-dependent manner.
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PMID:The pap1(+) gene of fission yeast is transcriptionally regulated by nitrosative and nutritional stress. 1824 28


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