Figure 1. ATRX is a multidomain-containing chromatin remodeler. The ADD domain of ATRX (dark blue box) contains both a GATA-like domain and a PHD and “reads” the H3K9me3 modification.^6,21-23 We reported the in vivo interaction between the N-terminal 841 amino acids of ATRX with macroH2A1 (dashed red line).¹⁹ ATRX interacts with HP1α via a PxVxL motif present in the indicated region (orange box).¹⁶ Of note, while the interaction between EZH2 and ATRX (hatched blue box) was detected by yeast two hybrid,¹⁷ it remains to be seen if this persists in vivo and if indeed the entire region depicted is required for this interaction.