Cell type specific expression of the salivary histatin 3 gene

Salivary histatins are histidine-rich polypeptides, which have an anti-microbial activity and inhibit proteases from oral bacteria. Histatins are also specifically expressed in salivary glands. However, it has not been clarified the expression mechanisms of those genes. We have cloned the histatin 3 gene promoter and its various deletion mutants were constructed luciferase reporter plasmids. The -2108 ～ -2082 region of the promoter worked as a positive transcriptional element in HSG cells (salivary gland). In contrast, their expressions were not observed in the other cell types. A protein bound to the region was 100 kDa by UV-cross linking analysis. Taken together, the expression of the histatin 3 gene may have cell type specificity.