Figure 3.

Jarid2 regulates epidermal SC proliferation and differentiation. Jarid2 modulates the recruitment of the PRC2 complex and the trimethylation of lysine 27 Histone H3 (H3K27Me3). This epigenetic mark represses the Arf4 locus, leading to repression of p16/p19. In Jarid2 cKO mice (K14Cre∷Jarid2^fl/fl), trimethylation of H3K27 is decreased and subsequently, p16 is upregulated leading to a delay in bulge SC activation and increased IFE differentiation. This effect could be related, at least partially, by a decrease in the recruitment of Ezh2, which that is involved in repressing of p16 and epidermal differentiation complex encompassing Filaggrin (Flg), Loricrin (Lor), Involucrin (Ivl) and late cornified envelope (Lce) genes in an AP1-dependent manner (Ezhkova et al, 2009). In the absence of Jarid2, cultured keratinocytes present a decrease in their clonogenic potential, suggesting that Jarid2 controls epidermal SC renewal.