Integrated Proteomic and Ubiquitinomic Reveal Ubiquitination Remodeling in Pelvic Organ Prolapse

Abstract Pelvic organ prolapse (POP) is characterized by localized vaginal-wall tissue failure, but post-translational regulation remains incompletely understood. We integrated quantitative proteomic and ubiquitinomic profiling of vaginal tissues from 10 women with POP and 8 controls. Differentially expressed proteins were enriched in ECM-associated, cytoskeletal, and adherens-junction pathways, whereas the ubiquitinome revealed reproducible site-specific changes. Integrated analysis highlighted β-catenin (CTNNB1) and collagen type III alpha 1 chain (COL3A1), including the previously reported CTNNB1 K233 site and two newly identified ubiquitination sites, CTNNB1 K672 and COL3A1 K674. Representative MS/MS spectra supported assignment of these sites. Together, these data define POP-associated ubiquitination remodeling and nominate adherens-junction and ECM-linked proteins for future functional validation.