Molecular Cloning of the cDNA and the Promoter of the Hamster Uteroglobin/Clara Cell 10-kDa Gene (ug/cc10): Tissue-Specific and Hormonal Regulation

Using the polymerase chain reaction on first-strand cDNAs from lung as well as on genomic DNA, we have cloned and sequenced both the cDNA and 1.5 kb of the promoter of the gene coding for hamster uteroglobin/Clara cell 10-kDa protein (UG/CC10), a secretory protein mainly synthesized in the pulmonary Clara cells. The amino acid sequence deduced from the cDNA indicated a preprotein of 96 residues, 19 of which corresponded to the signal peptide. The promoter region contained transcriptional regulatory elements conserved between species. Northern blot and S1 resistance assays detected high expression ofug/cc10in lung but not at all in other tissues. Expression in lung was positively controlled by glucocorticoids and was also subjected to a biphasic developmental regulation after birth. In agreement with the tissue-specific expression observedin vivo,the hamster promoter preferentially directed the expression of a reporter gene in cells derived from Clara cells. The results indicated that the tissue-specific expression and the regulation ofug/cc10varied considerably between species but all of them had a high expression in lung.