Keratin-associated protein 4-9 (KRTAP4-9)

Keratin-associated protein 4-9 (KRTAP4-9) is a member of the keratin-associated protein family, which are structural proteins highly expressed in the hair shaft. These proteins form a matrix that embeds and cross-links keratin intermediate filaments, providing rigidity, resilience, and strength to hair fibers through extensive disulfide bonding due to their high cysteine content. KRTAP4-9 belongs specifically to the "ultrahigh sulfur" KRTAP subfamily, defined by a cysteine content greater than 30%, and is involved in the physical properties that determine hair flexibility, strength, and morphology. There are no known roles in disease, biomarker utility, or therapeutic targeting for KRTAP4-9; its biological function is restricted to hair structure and morphology[1][2][4][7].

Other names

KAP4.9Keratin-associated protein 4.9Ultrahigh sulfur keratin-associated protein 4.9KRTAP4.9