NuSAP Safeguards Centriole Integrity to Mediate CEP57‐CEP152 Torus Recruitment for Proper Engagement

ABSTRACT Precise centrosome regulation is crucial for faithful cell division, yet how microtubule‐associated proteins (MAPs) contribute to centrosome integrity remains poorly understood. Here, we uncover a novel localization of NuSAP—a RanGTP‐regulated MAP—on centrioles using super‐resolution microscopy. NuSAP depletion disrupts centriole tubulin architecture, triggering premature centriole disengagement, compromising pericentriolar material (PCM) cohesion, and disrupting the spatial organization of the CEP57‐CEP63‐CEP152 torus assembly. Using TurboID‐based proteomics and biochemical assays, we identify CEP57 as a direct interactor of NuSAP. We further demonstrate that NuSAP is essential for the initial recruitment of the CEP57‐CEP63‐CEP152 complex to the proximal end of procentrioles. Based on these findings, we propose a novel two‐step model of torus complex recruitment, in which NuSAP‐dependent stabilization of centriole tubulin is required for early CEP57 loading. This discovery not only resolves a longstanding gap in our understanding of how MAP‐mediated tubulin stabilization contributes to centrosome organization but also provides a mechanistic framework for the hierarchical recruitment of the centriole torus complex.