Characterization of a Gene Encoding a Cysteine-Rich Keratin Associated Protein Synthesized Late in Rabbit Hair Follicle Differentiation

The study characterized a rabbit gene, rKAP4L1, which encoded a small cysteine-rich keratin-associated protein involved in hair follicle differentiation. This gene was part of a multigene family and was the first complete sequence identified for this family. The rKAP4L gene was expressed in the cortex of rabbit pelage hair follicles at a late stage of differentiation, after the synthesis of other major hair proteins. The protein was composed of 36% cysteine, had a molecular size of 13,593 daltons, and its sequence was based on a pentapeptide repeat, predicted to form a folded conformation with β-turns and β-sheets.