[摘要]：The formation of a stratified epidermis requires a carefully controlled balance between keratinocyte proliferation and differentiation Here we report the reciprocal effect on keratin expression of Delta Np63 pivotal in normal epidermal morphogenesis and maintenance and Skn-1a/Oct-11 a POU transcription factor that tnggers and regulates the differentiation of keratinocytes The expression of Skn-1a markedly down-regulated Delta Np63-driven K14 expression in luciferase reporter assays The extent of downregulation was comparable to the inhibition of Skn-1a-mediated K10 expression upon expression of Delta Np63 Delta Np63 mutated in the protein-protein interaction domain (SAM domain mutated in human ectodermal dysplasia syndrome) was significantly less effecting in downregulating K10 raising the possibility of a direct interaction among Skn-1a and Delta Np63 Immunolocalization in human skin biopsies revealed that the expression of the two transcription factors is partially overlapping Co-immunoprecipitation experiments did not however demonstrate a direct interaction between Delta Np63 and Skn-1a suggesting that the antagonistic effects of Skn-1a and p63 on keratin promoter transactivation is probably through competition for overlapping binding sites on target gene promoter or through an indirect interaction (C) 2010 Elsevier Inc All rights reserved
