Expression and regulation of gamma-glutamyl transpeptidase-related enzyme in tracheal cells.
Glutathione plays an essential role in protecting the pulmonary system from toxic insults. gamma-Glutamyl transpeptidase-related enzyme (GGT-rel) is a novel protein capable of cleaving the gamma-glutamyl peptide bond of glutathione and of converting leukotriene C4 to leukotriene D4. A rat homologue of GGT-rel was identified and was found to be highly expressed in cultures of differentiating rat tracheal epithelial (RTE) cells. The 2.6-kb cDNA predicts a 572-amino acid protein with 79% identity to human GGT-rel. GGT-rel was weakly expressed in normal trachea but was strongly induced by epidermal growth factor in cultures of RTE cells. GGT-rel was also highly expressed in lung tumors induced by inhalation of isobutyl nitrite. These results demonstrate that GGT-rel 1) is expressed in normal tracheal cells, 2) can be induced by epidermal growth factor, and 3) is elevated after chemical exposure. The induction of high levels of GGT-rel may play an important role in protecting the lung from oxidative stress or other toxic insults.
Potdar
P D
PD
Laboratory of Pulmonary Pathobiology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
Andrews
K L
KL
Nettesheim
P
P
Ostrowski
L E
LE
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002273:Carcinogens; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D017931:DNA Primers; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D008175:Lung Neoplasms / Q000139:chemically induced / Q000201:enzymology*; D008969:Molecular Sequence Data; D009573:Nitrites; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D051381:Rats; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014132:Trachea / Q000166:cytology / Q000201:enzymology*; D005723:gamma-Glutamyltransferase / Q000096:biosynthesis* / Q000737:chemistry
D002273:Carcinogens; D017931:DNA Primers; D009573:Nitrites; D004815:Epidermal Growth Factor; C069812:gamma-glutamyltransferase related enzyme; D005723:gamma-Glutamyltransferase; C018086:isobutyl nitrite