Transcriptional regulation of glyceraldehyde-3-phosphate dehydrogenase by 2,3,7,8-tetrachlorodibenzo-p-dioxin.
The action of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) on transcription and steady-state mRNA levels, protein expression, and enzymatic activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in cultured human keratinocytes was examined. GAPDH transcription increased as a function of time of exposure to TCDD, reaching a maximum of 23-fold after 8 days. Northern blot analysis showed a 4-fold increase in mRNA after 8 days exposure. Protein levels were increased 4-fold, and dehydrogenase activity by 5-fold, under the same exposure conditions. GAPDH is commonly thought of as a constitutive housekeeping gene and is often used as a loading control for northern blot analysis. Our data suggest that caution should be used when using GAPDH as an RNA control, especially in studies examining cell proliferation and carcinogenesis.
McNulty
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Center for Bioenvironmental Research, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA 70112-2699, USA.
Toscano
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D015152:Blotting, Northern; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000032:analysis / Q000096:biosynthesis*; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000201:enzymology*; D007700:Kinetics; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects*
D000072317:Polychlorinated Dibenzodioxins; D012333:RNA, Messenger; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases