FIGURE 8.

Summary of the effects of Hdac3 on chondrocyte differentiation. Hdac3 represses Phlpp1 transcription to facilitate Akt phosphorylation and activity on downstream effectors, mTOR and p70 SK6, which promotes protein translation. In the absence of Hdac3, Phlpp1 levels rise to dephosphorylate Akt as well as S6K. Although mTOR is not a direct substrate of Phlpp1, its phosphorylation levels decrease because Akt activity is suppressed when Phlpp1 is present. Filled circles represent an active phosphorylation (P) state. RTK, receptor tyrosine kinase; TF, transcription factor.