Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P36969 (phospholipid hydroperoxide glutathione peroxidase)
 344 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent findings in our laboratory suggested that in citrus cells the salt induction of phospholipid hydroperoxide glutathione peroxidase, an enzyme active in cellular antioxidant defense, is mediated by the accumulation of hydroperoxides. Production of hydroperoxides occurs as a result of non-enzymatic auto-oxidation or via the action of lipoxygenases (LOXs). In an attempt to resolve the role of LOX activity in the accumulation of peroxides we analyzed the expression of this protein under stress conditions and in cells of Citrus sinensis L. differing in sensitivity to salt. Lipoxygenase expression was induced very rapidly only in the salt-tolerant cells and in a transient manner. The induction was specific to salt stress and did not occur with other osmotic-stress-inducing agents, such as polyethylene glycol or mannitol, or under hot or cold conditions, or in the presence of abscisic acid. The induction was eliminated by the antioxidants dithiothreitol and kaempferol, thus once more establishing a correlation between salt and oxidative stresses. Analyses of both in vitro and in vivo products of LOX revealed a specific 9-LOX activity, and a very fast reduction of the hydroperoxides to the corresponding hydroxy derivatives. This suggests that one of the metabolites further downstream in the reductase pathway may play a key role in triggering defense responses against salt stress.
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PMID:Preferential induction of a 9-lipoxygenase by salt in salt-tolerant cells of Citrus sinensis L. Osbeck. 1128 1

Known eukaryotic selenocysteine (Sec)-containing proteins are animal proteins, whereas selenoproteins have not been found in yeast and plants. Surprisingly, we detected selenoproteins in a member of the plant kingdom, Chlamydomonas reinhardtii, and directly identified two of them as phospholipid hydroperoxide glutathione peroxidase and selenoprotein W homologs. Moreover, a selenocysteyl-tRNA was isolated that recognized specifically the Sec codon UGA. Subsequent gene cloning and bioinformatics analyses identified eight additional selenoproteins, including methionine-S-sulfoxide reductase, a selenoprotein specific to Chlamydomonas: Chlamydomonas selenoprotein genes contained selenocysteine insertion sequence (SECIS) elements that were similar, but not identical, to those of animals. These SECIS elements could direct selenoprotein synthesis in mammalian cells, indicating a common origin of plant and animal Sec insertion systems. We found that selenium is required for optimal growth of Chlamydomonas: Finally, evolutionary analyses suggested that selenoproteins present in Chlamydomonas and animals evolved early, and were independently lost in land plants, yeast and some animals.
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PMID:Selenoproteins and selenocysteine insertion system in the model plant cell system, Chlamydomonas reinhardtii. 1211 May 81

Arazyme is a novel protease produced by the HY-3 strain of Aranicola proteolyticus, which is a Gram-negative aerobic bacterium that has been isolated from the intestine of the spider Nephila clavata. This study focused on the hepatoprotective effect of Arazyme on carbon tetrachloride (CCl4)-induced acute hepatic injury in senescence marker protein 30 (SMP30) knock-out (KO) mice and SMP30 wild-type (WT) mice. WT mice and SMP30 KO mice were divided into eight groups as follows: (i) two negative control groups (G1, G5) which were treated with a single intraperitoneal (i.p.) olive oil injection. (ii) Two positive control groups (G2, G6) which received a single i.p. CCl4 (0.4mL/kg) injection. (iii) Two vitamin C-treated groups (G3, G7) which received a single oral administration of vitamin C (100mg/kg) and were injected with a single i.p. CCl4 (0.4mL/kg). (iv) Two Arazyme-treated groups (G4, G8) which received a single oral administration of Arazyme (500mg/kg) and were injected with a single i.p. CCl4 (0.4mL/kg). Through present study, we could find that Arazyme-treated groups showed decreased degree of liver injury, increased expression of SMP30, decreased expression of phospho-Smad3 (p-Smad3), elevated expression of antioxidant proteins including sorbitol dehydrogenase, dihydropteridine reductase (DHPR), dehydrofolate reductase (DHFR), NADH dehydrogenase, glutathione S-transferase kappa 1 (GSTK1) and phospholipid hydroperoxide glutathione peroxidase (PHGPx) compared with non-Arazyme-treated groups. Therefore, it is concluded that Arazyme plays a significant role in protecting injured hepatocytes by increasing the expression of SMP30, inhibiting the transforming growth factor-beta (TGF-beta)/Smad pathway and elevating the expression of antioxidant proteins.
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PMID:Hepatoprotective effect of Arazyme on CCl4-induced acute hepatic injury in SMP30 knock-out mice. 1830 47