Analysis of the Sheep Trichohyalin Gene: Potential Structural and Calcium-Binding Roles of Trichohyalin in the Hair Follicle

The study analyzed the sheep trichohyalin gene to understand its structure and function in hair follicles. Trichohyalin, a structural protein in the inner root sheath and medulla, has a molecular weight of 201,172 and is rich in glutamate, arginine, glutamine, and leucine, comprising over 75% of its amino acids. It features two sets of tandem peptide repeats and forms an elongated alpha-helical rod structure, though it lacks sequences for intermediate filament formation. The presence of two EF hand calcium-binding domains at the amino terminus suggested that trichohyalin had roles beyond structural support. It was expressed in various epithelia, including the tongue, hoof, rumen, and hair follicle.