RESUMO
Ubiquitination is one of the most major post-translational modifications playing important role in regulation of intra-cellular proteins' stability, degradation, localization and biological activity. However, these proteins are difficult to be detected due to their low abundance, short half-life. In this study, ubiquitin-binding domains (UBDs) were constructed to purify the ubiquitinated proteins from Hep3B cells. Ubiquitinated proteins and sites were detected by LC-MS/MS. A total of 1 900 potential ubiquitinated proteins were identified. Among them, 158 ubiquitinated sites were identified, belonging to 102 proteins. Bioinformatics analysis revealed that the enriched pathways of ubiquitinated proteins were closely related to tumor occurrence and development. The dysfunction of ubiquitin-proteasome has a high correlation with cell signaling and extracellular matrix changing in tumor cells.