Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have isolated a 1276-base pair cDNA from a rat heart cDNA library that encodes a novel thioredoxin (Trx2) of 166 amino acid residues with a calculated molecular mass of 18.2 kDa. Trx2 possesses the conserved thioredoxin-active site, Trp-Cys-Gly-Pro-Cys, but lacks structural cysteines present in all mammalian thioredoxins. Trx2 also differs from the previously described rat thioredoxin (Trx1) by the presence of a 60-amino acid extension at the N terminus. This extension has properties characteristic for a mitochondrial translocation signal, and the cleavage at a putative mitochondrial peptidase cleavage site would give a mature protein of 12.2 kDa. Western blot analysis from cytosolic, peroxisomal, and mitochondrial rat liver cell fractions confirmed mitochondrial localization of Trx2. Northern blot and reverse transcriptase-polymerase chain reaction analyses revealed that Trx2 hybridized to a 1.3-kilobase message, and it was expressed in several tissues with the highest expression levels in heart, muscle, kidney, and adrenal gland. N-terminally truncated recombinant protein was expressed in bacteria and characterized biochemically. Trx2 possessed a dithiol-reducing enzymatic activity and, with mammalian thioredoxin reductase and NADPH, was able to reduce the interchain disulfide bridges of insulin. Furthermore, Trx2 was more resistant to oxidation than Trx1.
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PMID:Cloning and expression of a novel mammalian thioredoxin. 900 39

The molecular basis of how rodent nongenotoxic hepatocarcinogens such as phenobarbitone cause liver-tumor formation is poorly understood. An early effect of phenobarbitone exposure is to induce hepatocyte proliferation transiently, and there is evidence that this may be important for subsequent tumor development. In this investigation, we have used the differential display reverse transcriptase polymerase chain reaction technique to analyze differential gene expression in male C57B1/10J mouse liver during the mitogenic phase of the phenobarbitone response. Seventy-seven putative differentially expressed cDNAs were isolated by differential display, and 13 of them were subsequently confirmed as being differentially expressed (both increased and decreased by phenobarbitone). Seven of the cDNAs were homologous to known mouse or human genes (carboxylesterase, coagulation factor X, amine N-sulphotransferase, human protein disulphide isomerase-related protein, cytochrome c oxidase subunit IV, golgin-245, thioredoxin reductase, betaine-homocysteine methyl transferase) and the remainder were novel. The expression pattern of the sulphotransferase was further characterized, and in mouse liver it was found to be significantly induced by phenobarbitone and not by five other rodent nongenotoxic hepatocarcinogens. In summary, the technique has enabled the identification of previously uncharacterized genes whose expression patterns are differentially altered by phenobarbitone in the mouse liver.
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PMID:Identification of phenobarbitone-modulated genes in mouse liver by differential display. 1063 Apr 19

Our previous study reported that oxysterol cholestane-3beta,5 alpha, 6 beta-triol (Triol) induced vascular smooth muscle cells (VSMCs) apoptosis, which was inhibited by selenium pretreatment. To further investigate the mechanisms of the inhibition, the glutathione peroxidase (GPx) activity, the total antioxidant capacity (T-AOC), the total superoxide dismutase (SOD) activity, and the level of lipid peroxidation (the content of malondialdehyde, MDA) of VSMCs were measured, and fluidity of cell membrane, reactive oxygen species (ROS) level, the reduction of mitochondrial membrane potential (Delta psi(m)), and the intracellular Ca(2+) in single cell were detected using several fluorescence indicators. Meanwhile, the mRNA levels of c-myc, bcl-2, GPx, and thioredoxin reductase (TR) were measured by reverse transcriptase polymerase chain reaction (RT-PCR) analysis. The results showed that the decrease of GPx activity, T-AOC, SOD activity, the fluidity of cell membrane, the Delta psi(m), and the mRNA expression of c-myc, bcl-2, GPx, and TR of VSMCs and the increase of MDA, ROS generation, and intracellular Ca(2+), significantly induced by Triol (10 microM, 24h) were inhibited to a different extent, respectively, when cells were pretreated with sodium selenite (50 nM, 12 or 24h) before exposure to Triol. These effects were time dependent and enhanced with prolongation of the time of pretreatment. In conclusion, the results in the present work showed that the mechanism of selenium inhibition of cell apoptosis induced by oxysterols in rat VSMCs was related with the antioxidation of selenoproteins.
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PMID:Mechanisms of selenium inhibition of cell apoptosis induced by oxysterols in rat vascular smooth muscle cells. 1603 82

In order to investigate proteins involved in early phase of conidia germination, proteomic analysis was performed using two-dimensional gel electrophoresis (2D-GE) in conjunction with MALDI-TOF mass spectrometry (MS). The expression levels of 241 proteins varied quantitatively with statistical significance (P<0.05) at the early phase of the germination stage. Out of these 57 were identified by MALDI-TOF MS. Through classification of physiological functions from Conserved Domain Database analysis, among the identified proteins, 21, 13, and 6 proteins were associated with energy metabolism, protein synthesis, and protein folding process, respectively. Interestingly, eight proteins, which are involved in detoxification of reactive oxygen species (ROS) including catalase A, thioredoxin reductase, and mitochondrial peroxiredoxin, were also identified. The expression levels of the genes were further confirmed using Northern blot and reverse transcriptase (RT)-PCR analyses. This study represents the first proteomic analysis of early phase of conidia germination and will contribute to a better understanding of the molecular events involved in conidia germination process.
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PMID:Proteomic analysis of early phase of conidia germination in Aspergillus nidulans. 1991 53