PKCη promotes a proliferation to differentiation switch in keratinocytes via upregulation of p27Kip1 mRNA through suppression of JNK/c-Jun signaling under stress conditions.

ABSTRACT: To maintain epidermal homeostasis, the balance between keratinocyte proliferation and differentiation is tightly controlled. However, the molecular mechanisms underlying this balance remain unclear. In 3D organotypic coculture with mouse keratinocytes and fibroblasts, the thickness of stratified cell layers was prolonged, and growth arrest and terminal differentiation were delayed when PKCη-null keratinocytes were used. Re-expression of PKCη in PKCη-null keratinocytes restored stratified cell layer thickness, growth arrest and terminal differentiation. We show that in 3D cocultured PKCη-null keratinocytes, p27(Kip1) mRNA was downregulated, whereas JNK/c-Jun signaling was enhanced. Furthermore, inhibition of JNK/c-Jun signaling in PKCη-null keratinocytes led to upregulation of p27(Kip1) mRN

SUBMITTER: Hara T 

PROVIDER: S-EPMC3122119 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature