TUFTELIN - ASPECTS OF PROTEIN AND GENE STRUCTURE

The acidic enamel protein tuftelin has now been cDNA cloned, sequenced and characterized in a number of vertebrate species. Recently, the bo vine tuftelin gene structure was elucidated. Cloning of the human tuft elin gene and partial sequencing of a number of exons have also been a chieved. Immunologically, the protein has been shown to be conserved t hroughout 550 million years of vertebrate evolution. The gene has been localized to the long arm of the autosomal chromosome 1. The mapping of the human tuftelin gene to a well-defined cytogenetic region could be important in understanding the etiology of autosomally inherited am elogenesis imperfecta, the most common hereditary disease of enamel. T he present paper reviews the primary structure, mRNA/cDNA structure, a nd gene structure of tuftelin. It describes its immunolocalization at the light microscope level and at the ultrastructural level in both th e ameloblast cells and in the extracellular enamel matrix. The timing of tuftelin expression and its possible roles in enamel formation are discussed.