Against The Rules: Human Keratin K80

The study investigated human keratin K80 and its splice variant K80.1, revealing K80's unique expression across various epithelial tissues and its structural similarity to type II hair keratins. K80 was found in a wide range of epithelia, forming intermediate filaments with over 20 type I keratins, and was notably present in hair follicles. K80.1 was more restricted, primarily detected in hair follicles and tongue papillae. The research highlighted K80's evolutionary significance, being one of the oldest keratins, and the novel occurrence of alternative splicing in keratins. The study emphasized K80's role in epithelial differentiation and its potential importance in hair follicle biology.