Trichohyalin (TCHH)

Intermediate filament-associated protein that associates in regular arrays with keratin intermediate filaments (KIF) of the inner root sheath cells of the hair follicle and the granular layer of the skin. It later becomes cross-linked into KIF by isodipeptide bonds.

It can serve as scaffold protein, together with involucrin, in the organization of the cell envelope or even anchor the cell envelope to the KIF network. It can be involved in its calcium-dependent postsynthetic processing during terminal differentiation.