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Published on: January 26, 2017
The human hGSTA5 gene encodes an enzymatically active protein
Sharda P Singh1, Ludwika Zimniak, Piotr Zimniak
1Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
Biochimica Et Biophysica Acta
|August 12, 2009
Summary
The human glutathione transferase hGSTA5 gene is functional, producing an active enzyme that conjugates 4-hydroxynonenal. This suggests its native promoter is active but expression is restricted.
Area of Science:
- Biochemistry
- Molecular Biology
- Enzymology
Background:
- Human Alpha-class glutathione transferases (GSTs) are crucial for detoxification.
- Experimental documentation of hGSTA5 expression was lacking despite in silico evidence of its potential.
- This study aimed to experimentally verify the functionality of hGSTA5.
Purpose of the Study:
- To determine if the human glutathione transferase hGSTA5 gene is functional.
- To investigate the enzymatic activity of the hGSTA5 protein.
- To explore the expression and activity of hGSTA5 in cellular systems.
Main Methods:
- Transfection of human K562 and HEK-293 cells with the hGSTA5 gene.
- Recovery and expression of hGSTA5 cDNA in bacterial (E. coli) and eukaryotic systems.
- Purification of the expressed protein and assessment of its glutathione transferase activity, particularly against 4-hydroxynonenal.
Main Results:
- Transfected cells produced mature, spliced hGSTA5 mRNA.
- The expressed hGSTA5 protein demonstrated catalytic activity, specifically conjugating 4-hydroxynonenal (4-HNE) with glutathione.
- Elevated 4-HNE-conjugating activity was observed in cell lysates, and a cell-free system produced active hGSTA5.
Conclusions:
- hGSTA5 is processed into a mature mRNA and translated into a catalytically active enzyme.
- The native hGSTA5 promoter is likely active but exhibits restricted spatial, temporal, or conditional expression patterns.
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