Figure 1. Model for epigenetic gene silencing in FRDA and activity of HDAC inhibitors.
Gene activity is governed by the balance of activities of the chromatin modifying enzymes, the histone acetyltransferases (HATs), histone deacetylases (HDACs), and histone methyltransferases (HMTases). Histone methylation (me at H3 lysine 9) provides a binding site for heterochromatin protein 1 (HP1), which has been shown to be involved in GAA repeat mediated gene silencing [2]. The HDAC inhibitor 4b was shown to reverse silencing [3]. Taken from Festenstein [54], with permission.