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 runon transcriptional assay, support the conclusion that thioredoxin gene is transcriptionally upregulated by retinol and/or its metabolites.