Identification and dissection of an enhancer controlling epithelial gene expression in skin

The study investigated the regulatory mechanisms of keratinocyte-specific gene expression in the skin, focusing on the enhancer elements of the K14 gene. Researchers identified DNase I hypersensitive sites (HSs) II and III as crucial for this regulation. HS III alone directed expression to inner root sheath (IRS) keratinocytes, while the combination of HSs II and III shifted expression to basal keratinocytes and the outer root sheath (ORS). The study highlighted the role of CACCC-box binding proteins, Sp1 family members, and other factors in this process, emphasizing the cooperative interaction of HSs and transcription factors. The research, involving transgenic mice, underscored the complex interplay of transcription factors required for tissue- and differentiation-specific expression in skin.