Histone deacetylation as a landmark for Sgo2 relocation from centromeres to subtelomeres during interphase

Shugoshin family proteins localize to centromeres and play pivotal roles in chromosome segregation during mitosis and meiosis. In fission yeast, the Shugoshin paralog Sgo2 relocates from centromeres to subtelomeres during interphase, where it contributes to gene repression by establishing a subtelomere-specific condensed chromatin structure known as the knob. However, the mechanisms underlying subtelomere-specific Sgo2 localization and knob formation during interphase remain poorly understood. Here, we identified Nts1, a component of the histone deacetylase complex, as a key regulator of Sgo2 localization through a genetic screen. Deletion of both nts1 ⁺ and set2 ⁺ (which encodes a histone H3-K36 methyltransferase) resulted in an almost complete loss of Sgo2 localization and knob formation at subtelomeres, indicating that Nts1 and Set2 function redundantly to target Sgo2 to subtelomeres. Notably, Nts1 localizes to subtelomeres during interphase and promotes histone H4 deacetylation, suggesting that histone deacetylation serves as a landmark for subtelomere-specific Sgo2 localization and knob formation.