Linked Life Data

8428933

Source:http://linkedlifedata.com/resource/pubmed/id/8428933

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1993-3-8
pubmed:databankReference
pubmed:abstractText
We have characterized a new selenium-dependent glutathione peroxidase, GSHPx-GI, by expressing a GSHPx-GI cDNA isolated from human hepatoma HepG2 cells in human mammary carcinoma MCF-7 cells, which have virtually undetectable expression of either the classical cellular enzyme, GSHPx-1, or GSHPx-GI at the protein level. One of the G418-resistant clones, neo-D1, expresses the transfected GSHPx-GI cDNA. This is based on 1) the presence of an additional GSHPx-GI DNA restriction fragment detected by Southern analysis; 2) the presence of a 1.9-kilobase (kb) GSHPx-GI mRNA in addition to the 1.0-kb endogenous mRNA by Northern analysis; and 3) the appearance of a 22-kDa 75Se-labeled protein which is absent in parental MCF-7 cells revealed by SDS-polyacrylamide gel electrophoresis. GSHPx-GI expressed in neo-D1 is a tetrameric protein localized in cytosol. GSHPx-GI does not cross-react with antisera against human GSHPx-1 or human plasma glutathione peroxidase (GSHPx-P). Similar substrate specificities are found for GSHPx-1 and GSHPx-GI; they both catalyze the reduction of H2O2, tert-butyl hydroperoxide, cumene hydroperoxide, and linoleic acid hydroperoxide with glutathione, but not of phosphatidylcholine hydroperoxide. GSHPx-GI mRNA was readily detected in human liver and colon, and occasionally in human breast samples, but not other human tissues including kidney, heart, lung, placenta, or uterus. In rodent tissues, GSHPx-GI mRNA is only detected in the gastrointestinal tract, and not in other tissues including liver. In fact, GSHPx-GI appears to be the major glutathione-dependent peroxidase activity in rodent GI tract. This finding suggests that GSHPx-GI could play a major role in protecting mammals from the toxicity of ingested lipid hydroperoxides. In conclusion, we have demonstrated that GSHPx-GI is the fourth member in the selenium-dependent glutathione peroxidase family, in addition to GSHPx-1, GSHPx-P, and phospholipid hydroperoxide glutathione peroxidase (PHGPX).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2571-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8428933-Amino Acid Sequence, pubmed-meshheading:8428933-Animals, pubmed-meshheading:8428933-Base Sequence, pubmed-meshheading:8428933-Cloning, Molecular, pubmed-meshheading:8428933-Cytosol, pubmed-meshheading:8428933-DNA, pubmed-meshheading:8428933-Gene Expression, pubmed-meshheading:8428933-Genes, pubmed-meshheading:8428933-Glutathione Peroxidase, pubmed-meshheading:8428933-Humans, pubmed-meshheading:8428933-Intestines, pubmed-meshheading:8428933-Isoenzymes, pubmed-meshheading:8428933-Mice, pubmed-meshheading:8428933-Molecular Sequence Data, pubmed-meshheading:8428933-Oligodeoxyribonucleotides, pubmed-meshheading:8428933-Proteins, pubmed-meshheading:8428933-RNA, Messenger, pubmed-meshheading:8428933-Rats, pubmed-meshheading:8428933-Selenoproteins, pubmed-meshheading:8428933-Transfection
pubmed:year
1993
pubmed:articleTitle
Expression, characterization, and tissue distribution of a new cellular selenium-dependent glutathione peroxidase, GSHPx-GI.
pubmed:affiliation
Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, California 91010.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't