Thioredoxin gene expression is transcriptionally up-regulated by retinol in monkey conducting airway epithelial cells

Using the differential hybridization technique, a cDNA clone, MT78, was isolated from the cDNA library of retinol-treated monkey tracheobronchial (TBE) epithelial cells. MT78 has a high sequence homology to human thioredoxin. The cDNA insert contains 506 nucleotides which encodes a peptide of 105 amino acids. The deduced peptide contains the highly conserved sequence Cys-Gly-Pro-Cys, found at the active site of all thioredoxins. The expression of the thioredoxin gene is stimulated 8-10 fold by vitamin A (retinol) in monkey TBE cells. The expression is significantly enhanced within 4 h after the vitamin A treatment and concurrent protein synthesis is not required for this enhancement. These results, in conjunction with the nuclear run-on transcriptional assay, support the conclusion that thioredoxin gene is transcriptionally up-regulated by retinol and/or its metabolites.