This project aims to systematically investigate the role of HSP27 in maintaining protein homeostasis (proteostasis) in U87-MG human glioblastoma cells. We performed three complementary quantitative proteomics analyses to compare HSP27 knockout (KO) and wild-type (WT) control groups. First, we characterized the ubiquitinome by enriching ubiquitinated peptides using an anti-K-ε-GG antibody to identify changes in ubiquitination sites and pathways. Second, we employed TME (tetramethylrhodamine) labelling coupled with copper-catalyzed click chemistry and streptavidin bead enrichment to profile misfolded proteins. Third, we isolated stress granule (SG) components via differential centrifugation to examine the protein composition of SGs upon HSP27 depletion. All samples were analyzed using LC-MS/MS-based 4D-FastDIA proteomics. This integrative dataset provides a comprehensive resource for understanding how HSP27 coordinates ubiquitin-proteasome pathway, misfolded protein clearance, and stress granule dynamics in glioblastoma cells.