Figure 3. Model depicting the dynamics of HP1α phosphorylation during G₁, G₂/early mitosis, and in later parts of mitosis. Phosphorylation of the N terminus of HP1α facilitates its association to the chromatin mark H3trimethylK9. NDR kinase associates with the chromo-shadow domain of HP1α and phosphorylates the hinge domain. Hinge-phosphorylated form of HP1α localizes to centromeres, associates with centromeric proteins (X/Y denote unknown proteins at centromere), and governs chromosome alignment (schematic adapted and modified from Chakraborty et al., 2014). Starting at metaphase, HP1α is dephosphorylated (presumably by PP1/PP2A), and this releases this form of HP1α and associated partners (bound specifically to hinge-phosphorylated HP1α) from the centromere.