The main regulatory region in the murine PSP gene is a parotid gland enhancer

The murine PSP gene is expressed at a high-level in the parotid glands. To extend the knowledge of parotid gland expression and develop tools for expr ession of heterologous proteins in this tissue, the regulation of the PSP g ene was studied using transgenic mice. High-level parotid gland expression of the PSP gene was indicated to depend on a novel regulatory region situat ed between -8.0 and -6.5 kb. Together with previous results this indicates that the main regulatory elements in the PSP gene are situated between -8.0 to -3.1 kb. This region was shown to activate a heterologous SV40 early pr omoter in the parotid glands of transgenic mice, suggesting that the PSP ge ne is controlled by enhancer sequences. A novel Psp derived 9.7 kb parotid gland expression cassette, Lama IV carrying all known regulatory regions in the PSP gene was expressed at high-levels in the parotid glands and should prove highly useful for expression of heterologous proteins in the saliva of transgenic mice.