The occurrence of profilaggrin and its processing in cultured keratinocytes.

An affinity-purified antibody to rat filaggrin detects filaggrin and profilaggrin in extracts of newborn rat epidermis, and a monoclonal antibody to human filaggrin, HF-1, detects the two proteins in extracts of human epidermis. Immunohistologic studies show that HF-1 reacts with keratohyaline granules of human epidermis and those seen in cultured human keratinocytes. Immunoblotting studies have demonstrated that profilaggrin is synthesized in both cultured human keratinocytes and in a long-lived line of cultured rat keratinocytes, but only in the latter is the protein processed to a product of the molecular weight of filaggrin.