The Catalog of Human Hair Keratins

The 2001 study cataloged human type II hair keratins, identifying six functional members divided into two groups, A and C, with distinct expression patterns in hair follicles. Group A keratins (hHb1, hHb3, hHb6) were found in the hair cortex, while Group C keratins (hHb2, hHb5) were located in the hair cuticle and matrix cells. The research used techniques like in situ hybridization and immunohistochemistry to map keratin expression, revealing complex dynamics in keratin pairing during hair differentiation. The study also noted a numerical imbalance between type I and type II keratins and highlighted evolutionary aspects, such as gene inactivation in humans compared to chimpanzees. The findings contributed to a comprehensive catalog of human hair keratins, enhancing the understanding of hair keratin complexity and suggesting the need for further research to fully understand the regulation of hair keratin expression.