University of Southern California researchers identify protein region shaping tooth enamel

Researchers at the University of Southern California have identified a specific protein region that plays a critical role in shaping tooth enamel. The study, published in the International Journal of Oral Science, focuses on a small segment of ameloblastin (Ambn), the second most abundant protein in developing enamel.

The team identified an amphipathic helix, known as the AH motif, which allows the protein to bind to cell membranes. This motif is evolutionarily conserved, with high similarity found across humans, pigs, and mice. Using CRISPR-Cas9 technology, scientists created mice with a deleted AH motif to observe the effects on enamel formation.

While the mutant protein could still self-assemble, its ability to interact with ameloblast cells—the cells responsible for laying down enamel—was significantly reduced. This discovery helps explain the molecular signaling that allows ameloblasts to polarize and create the highly ordered prism structures characteristic of mammalian enamel.