Nuclear protein extracts from tumor cells were prepared using a commercial extraction kit (Beyotime #P0027), quantified by BCA assay, and adjusted to 5 μg/μL in PBS containing 100 μM PMSF. For immunoprecipitation, 5 μg of anti-GLUD1 or control IgG antibody was incubated with nuclear lysates overnight at 4°C, followed by 4 h incubation with magnetic beads. Beads were washed (3× PBS) and proteins eluted in loading buffer (95°C, 5 min). Samples were resolved on 10% Omni-PAGE™ Hepes Plus gels, with excised bands processed for proteomics Analysis (APT Biotechnology). In brief, gel slices were reduced/alkylated, trypsin-digested (1:50 enzyme:protein, 37°C, 20 h), desalted, and analyzed by nano LC-MS/MS using a Q-Exactive HF-X system with a 120-min gradient (5-35% acetonitrile in 0.1% formic acid). MS parameters included: 70,000 resolution (MS1), 17,500 resolution (MS2), top-20 data-dependent acquisition, 27 eV HCD energy, and 30 s dynamic exclusion. Data were processed using MaxQuant 1.6.14 against the UniProt human database with standard search parameters (1% FDR).