Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:EXPT01586 (G418)
 2,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Xanthine Oxidoreductase (XOR) is the key enzyme in purine metabolism and also produces oxygen free radicals. As a continuation of our previous work, in this study, we constructed a retrovirus expression vector (pLNCX2-XOR) containing full length of XOR cDNA. Retrovirus was produced by the virus package cell line PT-67 following the transfection of PT-67 with pLNCX2-XOR and used to infect the human primitive neuroectodermal tumor cell line (PFSK). Infected PFSK cells were selected by G418 to establish cell line with stable expression of XOR. The expression of XOR in the cell line we established was confirmed by RT-PCR, Immunocytochemistry and XOR activity assay.
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PMID:[Establishment of human neuroectodermal tumor cell line (PFSK) with stable expression of xanthine oxidoreductase]. 1254 28

Aminoglycosides are antibacterial molecules that decrease translation accuracy by binding to the decoding aminoacyl-tRNA site (A site) on 16S ribosomal RNA. We have solved the crystal structure of an RNA fragment containing the A site bound to geneticin at 2.40A resolution. Geneticin, also known as G418, is a gentamicin-related aminoglycoside: it contains three rings that are functionalized by hydroxyl, ammonium and methyl groups. The detailed comparison of the distinctive behaviour of geneticin (binding to pro- and eukaryotic A sites) with the crystallographic, biochemical and microbiological results obtained so far for aminoglycoside-A site complexes offers new insights on the system. The two sugar rings constituting the neamine part common to most of the aminoglycosides bind to the A site, as already observed in the crystal structures solved previously with paromomycin and tobramycin. The essential hydrogen bonds involving ring I (to A1408) and ring II (to the phosphate oxygen atoms of the bulged adenine bases 1492 and 1493 and to G1494) are conserved and additional contacts are observed from ring III (to phosphate oxygen atoms of G1405 and U1406). The present work illustrates a molecular basis of the range in sensitiveness exhibited by geneticin towards common point A site mutations associated to resistance phenotypes. In addition, analysis and comparisons of the structures cast light on the role played by the conserved U1406.U1495 pair in the recognition of the A site by aminoglycosides.
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PMID:Crystal structure of geneticin bound to a bacterial 16S ribosomal RNA A site oligonucleotide. 1258 61

Oxidoreductases such as glutaredoxin are a major class of enzymes that reversibly catalyze thiol-disulfide exchange reactions. Transfection experiments using geneticin (G418) selection to identify the specific protein S-thiolated substrates of glutaredoxin-1 (Grx-1) noted the curious phenomenon that nontransfected control cells treated with G418 had increased levels of Grx-1 expression. Varied concentrations of gentamicin, kanamycin, and hygromycin increased Grx-1 expression in a time- and dose-dependent fashion in human cultured retinal pigment epithelial cells. Reactive oxygen species formation after aminoglycoside exposure correlated directly to aminoglycoside treatment. Further indication that oxidation regulates Grx-1 expression was noted by the positive effect of phorbol 12-myristate 13-acetate, a known inducer of redox-sensitive AP-1 transcription factor. In agreement with this hypothesis was the finding that the physiologic reductant N-acetylcysteine decreased Grx-1 expression whereas tert-butyl hydroperoxide increased Grx-1 expression. Our data suggest that aminoglycosides increased Grx-1 expression in response to oxidative stress.
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PMID:Endogenous oxidoreductase expression is induced by aminoglycosides. 1274 50

To assess sources of variation in nuclear transfer efficiency, bovine fetal fibroblasts (BFF), harvested from six Jersey fetuses, were cultured under various conditions. After transfection, frozen-thawed lung or muscle BFF donor cells were initially cultured in DMEM in 5% CO(2) and air and some were transferred to MEM, with 5% or 20% O(2) or 0.5% or 10% serum and G418 for 2-3 wk. Selected clonal transfected fibroblasts were fused to enucleated oocytes. Fused couplets (n = 4007), activated with ionomycin and 6-dimethylaminopurine, yielded 927 blastocysts, and 650 were transferred to 330 recipients. Fusion rate was influenced by oxygen tension in a fetus-dependent manner (P < 0.001). Blastocyst development was influenced in a number of ways. Hip fibroblast generated more blastocysts when cultured in MEM (P < 0.001). The influence of serum concentration was fetus dependent (P < 0.001) and exposing fibroblast to low oxygen was detrimental to blastocyst development (P < 0.001). Cells from two of the six fetuses produced embryos that maintained pregnancies to term, resulting in eight viable calves. Pregnancy rates 56 days after transfer for the two productive donor fetuses, was at least double that of other recipients and may provide a fitness indicator of BFF cell sources for nuclear transfer. We conclude that a significant component in determining somatic cell nuclear transfer success is the source of the nuclear donor cells.
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PMID:Cell donor influences success of producing cattle by somatic cell nuclear transfer. 1499 11

Ergosterol is a principal sterol of fungi. It is a raw material for production of vitamin D2, hydrocortisone, progesterone and brassinolide. Synthesis of ergosterol requires molecular oxygen, and low oxygen tensions was reported to dramatically reduce ergosterol concentration. Vitreoscilla Hemoglobin Gene (vgb), a homodimeric hemoglobin gene from Gram-negative obligate aerobic bacterium Vitreoscilla, enables a higher specific cellular oxygen uptake rate, it also improves the oxygen transportation. In this study, recombinant plasmid pVgb-kanMX4 containing Vitreoscilla Hemoglobin Gene (vgb) and geneticin (G418) was constructed and transformed into Saccharomyces cerevisiae 1190 for enhanced ergosterol production. With sufficient oxygen supply, the ergosterol contents of recombinant and wild type strains grown in shake flasks were 1.07% and 0.573%, respectively. Under oxygen limitation condition, ergosterol contents in recombinant and wild type strains were reduced to 0.39% and 0.25%, respectively. In a 30 hours fermentation study conducted in a 5 liter fermentor, 15.1 g/L Cell Dry Weight (CDW) containing 1.38% ergosterol was obtained from growth of the recombinant strains; Only 14.8 g/L CDW containing 0.9% ergosterol was produced by the wild type strain. These results demonstrated that vgb played a role in enhancing ergosterol production.
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PMID:[Enhanced ergosterol production by recombinant Saccharomyces cerevisiae 1190 harboring Vitreoscilla hemoglobin gene (vgb)]. 1597 21

The full length cDNA of SARS coronavirus nucleocapsid (N) protein was amplified by PCR and cloned into yeast expression vector pPIC3.5K to generate expression vector pPIC3.5K-SCoVN. The plasmid was linearized and then transformed into P. pastoris (His- Mut+) by electroporation method. His+ Mut+ recombinant strains were screened on G418-RDB and MM/MD plates, and further confirmed by PCR. The influence of various inducing media, dissolved oxygen(DO) and the different final concentration of methanol was subsequently investigated. The results showed that the FBS medium was optimal for recombinant N protein expression and growth of the recombinant strain. The optimal final concentration of methanol is 1% (V/V), and the DO has a significant effect on recombinant N protein expression and growth of recombinant strain. The recombinant N protein expressed was about 6% of the total cell proteins, 410 mg/L of recombinant N protein and 45 OD600 were achieved in shake flask. Western-blot showed that the recombinant N protein had high specificity against mouse-anti-N protein-mAb and SARS positive sera, but had no cross-reaction with normal human sera. The result of scale-up culture in fermemtator demonstrated that 2.5g/L of recombinant N protein and the maximum cell 345 OD600 of were achieved, which was 6.1 times and 7.7 times higher than that in shake flask. So this study provide a basis for further researches on the early diagnosis of SARS and the virus reproduction and pathology reaction of SARS coronavirus.
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PMID:[Expression of the recombinant SARS coronavirus nucleocapsid protein in Pichia pastoris and identification of its bioactivity]. 1617 89

Induction of CYP2E1 by ethanol is one mechanism by which ethanol causes oxidative stress and alcohol liver disease. Although CYP2E1 is predominantly found in the endoplasmic reticulum, it is also located in rat hepatic mitochondria. In the current study, chronic alcohol consumption induced rat hepatic mitochondrial CYP2E1. To study the role of mitochondrial targeted CYP2E1 in generating oxidative stress and causing damage to mitochondria, HepG2 lines overexpressing CYP2E1 in mitochondria (mE10 and mE27 cells) were established by transfecting a plasmid containing human CYP2E1 cDNA lacking the hydrophobic endoplasmic reticulum targeting signal sequence into HepG2 cells followed by G418 selection. A 40-kDa catalytically active NH2-terminally truncated form of CYP2E1 (mtCYP2E1) was detected in the mitochondrial compartment in these cells by Western blot analysis. Cell death caused by depletion of GSH by buthionine sulfoximine (BSO) was increased in mE10 and mE27 cells as compared with cells transfected with empty vector (pCI-neo). Antioxidants were able to abolish the loss of cell viability. Increased levels of reactive oxygen species and mitochondrial 3-nitrotyrosine and 4-hydroxynonenal protein adducts and decreased mitochondrial aconitase activity and mitochondrial membrane potential were observed in mE10 and mE27 cells treated with BSO. The mitochondrial membrane stabilizer, cyclosporine A, was also able to protect these cells from BSO toxicity. These results revealed that CYP2E1 in the mitochondrial compartment could induce oxidative stress in the mitochondria, damage mitochondria membrane potential, and cause a loss of cell viability. The accumulation of CYP2E1 in hepatic mitochondria induced by ethanol consumption might play an important role in alcohol liver disease.
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PMID:Overexpression of CYP2E1 in mitochondria sensitizes HepG2 cells to the toxicity caused by depletion of glutathione. 1638 Mar 84

In the present study, nuclear transferred embryos (NTEs) were reconstructed by using pig fetal fibroblasts as donors and in vitro matured oocytes as recipients. The effects of G418 selection on donor cells, duration of IVM of prepubertal gilt oocytes and oxygen tension in IVM of oocytes were investigated. The results were as follows: (i) When G418 selected cells expressing GFP were used as donors, the cleavage rate of NTEs decreased drastically in comparison to NTEs derived from donors without antibiotic selection (47.5% vs. 71.6%, p < 0.05). For the blastocyst rate, no significant difference was observed between two groups (10% vs. 10.4%, p > 0.05). (ii) The rate of nuclear maturation of oocytes increased significantly when IVM duration time was extended from 36 to 42 h (83.6% vs. 96.7%, p < 0.05). However, no statistical difference was observed between NTEs derived from oocytes of 36 h IVM group and NTEs from oocytes of 42 h IVM group in the rates of cleavage (59.3% vs. 73.6%, p > 0.05) and blastocyst formation (9.3% vs. 13.2%, p > 0.05); (iii) no significant difference was observed between NTEs reconstructed from oocytes matured under lower oxygen (7% O2) tension and NTEs derived from oocytes matured under higher oxygen tension (20% O2) in cleavage rate (70.6% vs. 67.1%, p > 0.05) and blastocyst rate (11.8% vs. 12.3%, p > 0.05). These results suggest that: (i) G418 selection does not have a significant effect on cleavage rate of NTEs expressing GFP. (ii) Nuclear maturation is greatly improved by prolonging IVM duration from 36 to 42 h, while no significant differences were observed for developmental potential of transgenic embryos. Thus IVM 42 h is the better choice in order to obtain maximum number of M II oocytes as recipients. (iii) Lower oxygen tension and higher oxygen tension in IVM have no significant effect on development of cloned embryos.
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PMID:Production of porcine cloned transgenic embryos expressing green fluorescent protein by somatic cell nuclear transfer. 1670 20

This study presents morphological and biochemical evidence of programmed cell death (PCD) in Entamoeba histolytica induced by exposure of trophozoites to the aminoglycoside antibiotic G418. Morphological characteristics of PCD, including cell shrinkage, reduced cellular volume, nuclear condensation, DNA fragmentation and vacuolization were observed, with preservation of trophozoite membrane integrity. PCD is orchestrated biochemically by alterations in intracellular ion fluxes. In G418-treated trophozoites, overproduction of reactive oxygen species (ROS), decreased intracellular K+, increased cytosolic calcium, and decreased intracellular pH levels were observed. However, externalization of phosphatidylserine was not detected. These results suggest that amoebae can undergo PCD under stress conditions, and that this PCD shares several properties with PCD reported in mammals and in a variety of unicellular organisms.
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PMID:Programmed cell death in Entamoeba histolytica induced by the aminoglycoside G418. 1797 94

NADPH oxidase (Nox4) produces reactive oxygen species (ROS) that are important for vascular smooth muscle cell (SMC) behavior, but the potential impact of Nox4 in stem cell differentiation is unknown. When mouse embryonic stem (ES) cells were plated on collagen IV-coated dishes/flasks, a panel of SMC-specific genes was significantly and consistently upregulated. Nox4 expression was markedly correlated with such a gene induction as confirmed by real-time PCR, immunofluorescence, and Western blot analysis. Overexpression of Nox4 specifically resulted in increased SMC marker production, whereas knockdown of Nox4 induced a decrease. Furthermore, SMC-specific transcription factors, including serum response factor (SRF) and myocardin were activated by Nox4 gene expression. Moreover, Nox4 was demonstrated to drive SMC differentiation through generation of H(2)O(2). Confocal microscopy analysis indicates that SRF was translocated into the nucleus during SMC differentiation in which SRF was phosphorylated. Additionally, autosecreted transforming growth factor (TGF)-beta(1) activated Nox4 and promoted SMC differentiation. Interestingly, cell lines generated from stem cells by Nox4 transfection and G418 selection displayed a characteristic of mature SMCs, including expression of SMC markers and cells with contractile function. Thus we demonstrate for the first time that Nox4 is crucial for SMC differentiation from ES cells, and enforced Nox4 expression can maintain differentiation status and functional features of stem cell-derived SMCs, highlighting its impact on vessel formation in vivo and vascular tissue engineering in the future.
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PMID:Embryonic stem cell differentiation into smooth muscle cells is mediated by Nox4-produced H2O2. 1903 41


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