iProXProteomicsDuo MaoHomo Sapienshttp://www.iprox.org/page/project.html?id=IPX0014729000maod6@mail.sysu.edu.cnInstitute of Precision Medicine, The First Affiliated Hospital of Sun Yat-Sen UniversityiProXfalseNuclear Proteomics in Senescent Cells via NCP-Mediated Photocatalytic Proximity LabelingSpatiotemporal profiling of nuclear-associated proteomes is crucial for elucidating disease mechanisms, identifying key therapeutic targets1-2, and guiding the design of effective drugs. Currently, proximity labeling (PL) using genetically transfected enzymes or photocatalyst-based probes has emerged as a powerful tool for proteomic mapping. However, these approaches are limited by their incompatibility with hard-to-transfect cells and primary tissues, as well as by the lack of efficient nucleus-targeting strategies. In this study, we developed a photocatalytic proximity labeling strategy (Pc-PL) that enables efficient enrichment of nuclear-associated proteins by combining a nucleus-targeted photosensitizer (NCP) with photocatalysis-mediated reactive biotin labeling. Compared with traditional photocatalysts such as chlorin e6 and rose bengal, NCP exhibited superior nuclear accumulation across various cell types. Cellular experiments confirmed that NCP-mediated photoactivation precisely localized biotin labeling within the nucleus, enabling selective enrichment of nuclear proteins via subsequent streptavidin-based magnetic capture. Coupling Pc-PL with quantitative mass spectrometry enabled high-resolution mapping of nuclear proteomes and led to the discovery of previously unrecognized senescence-associated regulators, including TMPO. Collectively, these findings establish Pc-PL as an innovative and versatile tool for high-resolution nuclear proteomics, offering broad potential for target discovery and drug development.Tue Dec 16 00:00:00 GMT 2025PXD0720689606