Keratin 15 Promotes a Progenitor Cell State in Basal Keratinocytes of Skin Epidermis

The study explores the role of Keratin 15 (K15) in maintaining a progenitor cell state in basal keratinocytes of the skin epidermis. It highlights that K15 promotes a progenitor state by allowing nuclear localization of YAP1, a key regulator of cell proliferation and differentiation, due to its inability to bind 14-3-3σ proteins, unlike Keratin 14 (K14). This results in a higher K15:K14 ratio, supporting progenitor characteristics and influencing skin morphology, such as increased skin thickness and hair follicle length. The findings suggest that K15 plays a crucial role in skin regeneration and repair, with potential implications for therapeutic strategies targeting skin-related disorders.