Trichohyalin (TCHH)

Trichohyalin is a large intermediate filament-associated structural protein encoded by the TCHH gene, primarily found in the inner root sheath of the hair follicle and other specialized and mechanically strong epithelial tissues such as the granular layer of the epidermis and hard palate[2][4]. It forms frequent cross-links with itself and with keratin intermediate filaments, providing mechanical strength and stability to the hair follicle and associated tissues. Trichohyalin acts as a cross-bridging protein, reinforcing the cornified cell envelope and anchoring the cell envelope to the keratin cytoskeleton[1][3]. Structurally, it is highly charged, predominantly alpha-helical, and contains EF-hand-like calcium-binding domains. The protein undergoes post-translational modifications by peptidylarginine deiminases and transglutaminases, which further stabilize it through cross-linking and conversion of arginines to citrullines[1][2][3]. Mutations or loss of function can result in uncombable hair syndrome, and it may serve as an autoantigen in alopecia areata[2][4]. There are emerging roles for trichohyalin methylation status as a potential biomarker in metastatic cancers[4]. Trichohyalin is not a classic therapeutic target, such as a receptor, enzyme, or transporter, and there are no known drugs that directly interact with or target this protein.

Other names

TCHHTHHTHLTRHYUHS3trichohyalin