A mammalian bicistronic transcript encoding two dentin-specific proteins.

We previously reported that the cDNA for dentin phosphophoryn, a non-collagenous protein involved in dentin mineralization, was located immediately downstream from the 3' end of dentin sialoprotein, another functionally related non-collagenous dentin protein (Ritchie, H. H., and Wang, L-H. (1996) J. Biol. Chem. 269, 3689-3702). We now demonstrate unequivocally that at the genomic level in mammal, these two functionally related proteins are indeed transcribed as one transcriptional unit suggesting that their combined presence at specific mineralization sites in tooth germ is mandatory if dentin mineralization is to proceed.