A major histidine-rich protein component of the keratohyalin granules (filament-aggregating protein) that is present in the suprabasal cells of mammalian epidermis. It is produced as a large polyprotein precursor (4061 aa) which is proteolytically cleaved into ten to twelve individual functional filaggrin peptides of ~50 aa as a final step in differentiation. Filaggrin peptides cause aggregation of the keratin cytoskeleton and the granular cells collapse into flattened squames. The aggregated keratin is further stabilized by crosslinking by a transglutaminase. Mutations in filaggrin are responsible for ichthyosis vulgaris and are a major predisposing factor for atopic dermatitis, but not for asthma.
Subjects: Medicine and Health — Chemistry.