SUMOylation stabilizes sister kinetochore biorientation to allow timely anaphase

During mitosis, sister chromatids attach to microtubules from opposite poles, called biorientation. Sister chromatid cohesion resists microtubule forces, generating tension, which provides the signal that biorientation has occurred. How tension silences surveillance pathways prevent cell cycle progression and correct erroneous kinetochore–microtubule attachments remains unclear. Here we show SUMOylation dampens error correction allow stable kinetochore timely anaphase onset. The Siz1/Siz2 SUMO ligases modify pericentromere-localized shugoshin (Sgo1) protein before its tension-dependent release chromatin. Sgo1 reduces binding phosphatase 2A (PP2A), weakening of this interaction is important for Unstable in SUMO-deficient cells associated with persistence chromosome passenger complex (CPC) at centromeres, CPC subunit Bir1 also contributes We propose acts a combinatorial manner facilitate dismantling machinery within pericentromeres thereby sharpen metaphase–anaphase transition.