Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.5.1.18 (glutathione S-transferase)
22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The erythrocytes from control (C), diabetic (D) and insulin-treated diabetic (D+I) rats were separated into three ageing groups (TAG) i.e., light dense (young cells), intermediate-dense (middle-aged cells) and heavy-dense (old aged cells) samples. The activities of enzymes and metabolites changed from young to old cells in the following manner: (1) Increase of CAT in TAG and a lower level in D and D+I (2) Decrease of GPx in TAG but a low level in D (3) Increase of GR in TAG but a higher level in D, (4) Increase of GST in C and a decrease in D with a higher level in young cells and a lower level in middle-aged and old cells. The reversal of enzyme was more in young cells of D+I (5) Increase of GSH in TAG, a low level in D and a high level in D+I (6) Increase of GSSG in TAG, a high level found only in young cells of D. The results show that young red cells are affected more significantly in diabetes than other age cell types.
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PMID:Ageing erythrocytes and alloxan diabetes: I. A possible role of catalase, GSH, GSSG, and GSH-enzymes in decreasing defence system. 829 96

We report the characterization of a CAAT enhancer-binding protein (C/EBP) (NF-IL6) element encompassing the region from -174 to -166 of the U3 long terminal repeat (LTR) region of HIV-1. This C/EBP cis sequence was found to bind to C/EBPbeta and C/EBPdelta factors in DNA band shift assay. Transfection of NTera-2 cells with a HIV-1-LTR CAT construct (pC15CAT), together with C/EBPbeta or C/EBPdelta expression plasmids showed that C/EBP proteins strongly activated the HIV-1 promoter. Deletions encompassing the C/EBP-binding site resulted in the enhancement of the LTR activation mediated by C/EBP proteins, suggesting that other sequences located 3' to -170 were indeed the target for C/EBP factors. This possibility was confirmed by using the pCD54E9CAT plasmid, in which the NF-kappaB enhancer was inserted 5' to the HIV-1 LTR TATA box. A NF-kappaB1(p50) expression plasmid was also utilized to test for functional co-operation between NF-kappaB and C/EBP factors. We observed that p50 middle dotC/EBPbeta and p50 middle dotC/EBPdelta complexes were generated in tested cells and strongly activated the HIV-1 LTR by binding to the NF-kappaB sequences. The physical association of NF-kappaB1(p50) with C/EBP factors was assayed by direct interaction of in vitro translated p50 proteins with C/EBPbeta or C/EBPdelta produced as glutathione S-transferase fusion proteins. Moreover, p50 middle dotC/EBPbeta complexes were observed in vivo by using DNA affinity studies with biotinylated NF-kappaB oligonucleotides. By using mutant forms of p50 or C/EBPbeta proteins we found that the transactivation of HIV-1 LTR by p50 middle dotC/EBPbeta complexes required the DNA-binding domain of p50 and the transcription activation domain of C/EBPbeta.
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PMID:Regulation of HIV-1 long terminal repeats by interaction of C/EBP(NF-IL6) and NF-kappaB/Rel transcription factors. 879 13

The trans-activator protein (Tat) of HIV-1 plays an important role in viral pathogenesis. Since Tat has been shown to alter expression of a number of host cellular genes, we have investigated the role of Tat in modulating gene expression and differentiation in hematopoietic progenitor cells. Tat protein was introduced in K562 cells, a human hematopoietic progenitor cell line, by either scrape-loading onto HeLa (HL)-tat cells or direct electroporation of an affinity-purified glutathione S-transferase (GST)-Tat fusion protein. Under these conditions, butyric acid-induced hemoglobin production in K562 cells was suppressed by 65 and 52%, respectively. However, coculturing with wild-type HeLa cells or electroporation with the control GST protein did not decrease hemoglobin production. To confirm the presence of bioactive Tat protein within K562 cells, the cells were transiently transfected with a pHIV/LTR-CAT prior to the introduction of Tat. A 30- to 40-fold induction in CAT gene expression was observed in the transfected K562 cells, which were either cocultured with HL-tat or were electroporated with GST-Tat. Simultaneous transient transfection of K562 cells with a TAR expression plasmid, to compete for the availability of Tat protein, significantly downregulated the HIV LTR trans-activation by Tat. In addition, overexpression of the TAR RNAs in K562 cells was able to downregulate the suppressive effect of Tat on butyric acid-induced differentiation. RT-PCR analysis of the total RNAs isolated from these cells demonstrated that Tat protein suppressed the butyric acid-induced gamma-globin gene expression by an average of 54% without affecting the level of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNAs. These data indicate that the viral Tat protein plays a significant role in abrogating erythroid differentiation in K562 cells.
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PMID:Effect of HIV type 1 Tat protein on butyric acid-induced differentiation in a hematopoietic progenitor cell line. 891 78

Chemoprevention involves the use of natural or synthetic substances to reduce the risk of developing cancer. Two dietary components capable of mediating chemopreventive activity in animal models by modulation of drug-metabolizing enzymes are sulforaphane, an aliphatic isothiocyanate, and brassinin, an indole-based dithiocarbamate, both found in cruciferous vegetables. We currently report the synthesis and activity of a novel cancer chemopreventive agent, (+/-)-4-methylsulfinyl-1-(S-methyldithiocarbamyl)-butane (trivial name, sulforamate), an aliphatic analogue of brassinin with structural similarities to sulforaphane. This compound was shown to be a monofunctional inducer of NAD(P)H:quinone oxidoreductase [quinone reductase (QR)], a Phase II enzyme, in murine Hepa 1c1c7 cell culture and two mutants thereof. Induction potential was comparable to that observed with sulforaphane (concentration required to double the specific activity of QR, approximately 0.2 microM), but cytotoxicity was reduced by about 3-fold (IC50 approximately 30 microm). In addition, sulforaphane, as well as the analogue, increased glutathione levels about 2-fold in cultured Hepa 1c1c7 cells. Induction of QR was regulated at the transcriptional level. Using Northern blotting techniques, time- and dose-dependent induction of QR mRNA levels were demonstrated in Hepa 1c1c7 cell culture. To further investigate the mechanism of induction, HepG2 human hepatoma cells were transiently transfected with QR-chloramphenicol acetyltransferase plasmid constructs containing various portions of the 5'-region of the QR gene. Sulforaphane and the analogue significantly induced (P < 0.0001) CAT activity at a concentration of 12.5 microM by interaction with the antioxidant responsive element (5-14-fold induction) without interacting with the xenobiotic responsive element. Moreover, both compounds significantly induced mouse mammary QR and glutathione S-transferase activity (feeding of 3 mg/mouse intragastric for 4 days), whereas the elevation of hepatic enzyme activities was less pronounced. Both sulforaphane and the analogue were identified as potent inhibitors of preneoplastic lesion formation in carcinogen-treated mouse mammary glands in organ culture (84 and 78% inhibition at 1 microm, respectively). On the basis of these results, the sulforaphane analogue can be regarded as a readily available promising new cancer chemopreventive agent.
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PMID:Cancer chemopreventive potential of sulforamate, a novel analogue of sulforaphane that induces phase 2 drug-metabolizing enzymes. 900 May 67

The c-mos gene is transcribed in male and female germ cells, in differentiating myoblasts and in 3T3 cells from cell-specific promoters. We characterized the rat testis promoter, which contains a TATA-box and one binding site for a testis-specific transcription factor TTF-D, as well as a region which can act as enhancer, which is located approx. 2 kb upstream of the c-mos AUG start codon. It binds three factors at sites I, II and III as determined in DNAse I footprint assays. We demonstrated that a member of the NF-1/CTF family of transcription factors binds site II. Here we report the cloning of the protein that binds to enhancer site III. This protein is the rat homolog of human hCut/CDP, mouse Cux/CDP and canine Clox. hCut/Cux/CDP/Clox (hereafter called Cux/CDP), a 160 kDa protein containing multiple repeats and a homeodomain, negatively regulates the mammalian c-myc, gp91-phox and N-Cam genes. Using bacterially produced murine GST-Cux fusion proteins and GST-Cux deletion mutants, we find that Cux repeat CR3 and the homeodomain are both required for efficient binding to enhancer site III. Mouse lung and testis nuclear Cux/CDP bind to site III as determined in electrophoretic gel mobility supershift assays using two different anti-hCut specific monoclonal antibodies. Transfections of CAT constructs containing the enhancer fragment linked to a minimal promoter demonstrated that Cux/CDP represses c-mos enhancer activity.
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PMID:Cux/CDP homeodomain protein binds to an enhancer in the rat c-mos locus and represses its activity. 913 May 95

Seasonal variation in the activity of antioxidant enzymes (superoxide dismutase (EC 1.15.1.1.; SOD), catalase (EC 1.11.1.6; CAT), glutathione peroxidase (EC 1.11.1.9; GSH-Px), glutathione reductase (EC 1.6.4.2; GR), glutathione-S-transferase (EC 2.5.1.18; GST) and low-molecular-weight antioxidants: ascorbic acid (AsA), vitamin E (VIT E) and glutathione (CSH+GSSG) were examined in the brain of the ground squirrels (Citellus citellus) maintained at 30 degrees C during the whole year. The highest activity (per mg protein) of antioxidant defense (AD) enzymes was found in the spring and was much lower in the summer. A further decrease in activity of CAT, GSH-Px and GST was observed in the winter. The highest levels of AsA and glutathione were recorded in winter in comparison with spring and summer. AD system in the brain of the ground squirrel and rates (maintained at thermoneutrality) exposed to low temperature (4 degrees C) for 3, 6 or 24 hr during the summer was studied as well. Summer was chosen as a period of stable euthermia for ground squirrels and in thermoregulation similar to rats. Consumption of free fatty acid and glucose during the acute exposure to low temperature was found to be species specific. In the ground squirrel, an increase in the specific activities of SOD, after 3, 6 and 24 hr, CAT after 3 and 6 hr and GR after 6 hr of exposure to low temperature was detected. When activities were expressed in U/g wet mass, an increase of SOD after 3, 6 and 24 hr (P < 0.02, P < 0.02, P < 0.005) and CAT and GSH-Px 3 hr (P < 0.01) upon exposure to low temperature was observed. In the rats, no changes in the specific activities of these enzymes after exposure to low temperature were recorded and only an increase in GST activity (U/g wet mass) after 6 hr exposure was registered. Low-molecular-weight AD components in both animal species were unchanged upon short-term exposure to low temperature. The species-specific differences in brain AD between the rats and the ground squirrels after short exposure to low temperature may be ascribed to seasonal changes of the brain activity in the latter.
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PMID:Seasonal variation in the antioxidant defense system of the brain of the ground squirrel (Citellus citellus) and response to low temperature compared with rat. 921 14

To examine effects of exogenous Cd on the kidney antioxidant defense system (AOS) and the possible protective role of Se against Cd toxicity, male Wistar albino rats (2 months old) were exposed during 30 days to oral intake of 200 ppm Cd (as CdCl2), 0.l ppm Se (as Na-selenite) or to the same doses of Cd / Se, simultaneously. Marked accumulation of Cd (23.44 +/- 0.69 micrograms/g w.m.) and marked alterations of AOS, resulting in kidney injury (renal pseudohypertrophy), were found in Cd-treated rats. Activities of total superoxide dismutase (SOC, EC 1.15.1.1), manganese-containing superoxide dismutase (MnSOD) and selenium-dependent glutathione peroxidase (Se GSH-Px, EG 1.11.1.9) were significantly reduced, whereas that of glutathione-S-transferase (CST, EC 2.5.1.18) and vitamin E (vit E) concentration were significantly increased in the kidneys of Cd-treated rats. Kidney catalase (CAT, EC 1.11.1.6) activity, ascorbic acid (AsA) and red blood cell glutathione (GSH, GSSG) levels were not markedly influenced by CD uptake. In kidneys of Se treated rats, the activities of total SOD, copper-zinc-containing superoxide dismutase (CuZnSOD) and GST were significantly increased Activities of kidney CAT and Se GSH-Px were largely unchanged, whereas significant increases of the kidney AsA and vit E concentrations occurred. In Cd + Se-cotreated rats, the kidney activities of MnSOD, CAT and Se GSH-Px, as well as vit E concentration, were the same as in controls, whereas CuZnSOD and GST activities and concentration of AsA exceeded normal values. These data indicate that Se only partially improves the AOS that is insufficient to prevent Cd-induced nephrotoxicity.
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PMID:Effect of cadmium and selenium on the antioxidant defense system in rat kidneys. 921 17

The activity of antioxidant defense (AD) enzymes--superoxide dismutase (SOD, EC 1.15.1.1.), catalase (CAT, EC 1.11.1.6.), glutathione peroxidase (GSH-Px, EC 1.11.1.9.), glutathione-S-transferase (GST, EC 2.5.1.18), glutathione reductase (GR, EC 1.6.4.2) and glutathione (GSH) content of the anemic Belgrade (b/b) laboratory rats--were measured and analyzed in liver, spleen, lung, heart, brain and testes in comparison with nonanemic controls. The activities of hepatic Mn SOD, CAT, GSH-Px and GST (P < 0.02, P < 0.01 and P < 0.005) were decreased in anemic, comparing with nonanemic animals, whereas the spleen CuZn SOD, Mn SOD, CAT and GSH-Px (P < 0.005, P < 0.02, P < 0.005 and P < 0.01) activities were increased. In the lung of anemic rats, Mn SOD, GSH-Px and GR (P < 0.005, P < 0.01, P < 0.05) activities were higher, whereas GST (P < 0.01) activity was lower in relation to nonanemic ones. In anemic rats, heart Mn SOD (P < 0.05) activity was increased, brain GSH-Px (P < 0.005) activity was lower, whereas GR (P < 0.02) activity was higher compared with nonanemic controls. CuZn SOD (P < 0.05) activity in the testes was elevated and GSH-Px (P < 0.05) reduced in anemic animals. GSH content was decreased in the liver (P < 0.01), lung and brain (P < 0.005) and increased in the spleen (P < 0.02) of anemic rats in relation to the controls. Our data suggest phenotype specific differences in the AD system of the Belgrade (b/b) rat tissues in comparison with nonanemic controls.
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PMID:Activity of antioxidant defense enzymes and glutathione content in some tissues of the Belgrade (b/b) laboratory rat. 921 18

Transactivation of viral and host genes expression by hepatitis B virus X protein (HBx) is believed to be involved in hepatocarcinogenesis. The interaction of HBx with the tumor suppressor p53 and its inhibitory effect on p53 functions have been reported recently. However, the question of whether p53 is directly involved in HBx transactivation has not yet been addressed. In this study, we delineated the interaction sites of HBx and p53 using far-Western blotting and glutathione S-transferase-resin pull-down assays. The results indicate that the HBx-binding sites are located within the oligomerization and specific DNA-binding domains of p53 and that the p53-binding site was confined to a small region in the HBx transactivation domain. Mutual interference of the transactivations by HBx and p53 was detected by CAT assays in a transient transfection system. Strikingly, transactivation by HBx was observed in the p53-negative cells, Saos-2 and Hep3B, indicating that the transactivation and the p53-inhibiting functions of HBx are mutually interfering but distinct.
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PMID:The transactivation and p53-interacting functions of hepatitis B virus X protein are mutually interfering but distinct. 937 15

Glutathione S-transferase P1 (GST P1-1) is normally expressed exclusively in estrogen receptor negative (ER-) but not receptor positive (ER+) cultured breast cancer cells. We examined the role of proximal promoter elements in GST P1 gene expression in MCF7 (ER+, GST P1-) and HS578T (ER-, GST P1+) breast cancer cells. Transient transfection of GST P1 promoter-CAT reporter genes confirmed that the GST P1 TRE (-69 to -60) and the adjacent distal GC box (-56 to -51) are required for basal promoter activity in both cell lines. Other studies identified differences in the GST P1 promoter activity and DNA-protein interactions between the two cell lines. Electrophoretic mobility shift assay revealed a protein-TRE interaction that is unique to nuclear proteins derived from GST P1 expressing HS578T cells. Furthermore, a putative silencer region contained within sequences -130 to -70 selectively reduced GST P1 promoter-CAT reporter gene expression in MCF7 but not HS578T cells. While this cell-line specific silencer contributed to the level of GST P1 promoter activity observed in the two cell lines, analysis of cells stably transfected with a novel genomic GST P1 minigene vector established that the silencer is insufficient to completely repress GST P1 transcription in ER+, MCF7 cells that do not normally express endogenous GST P1.
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PMID:Contribution of proximal promoter elements to the regulation of basal and differential glutathione S-transferase P1 gene expression in human breast cancer cells. 954 Aug 34


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