Identification of Ubiquitinated Proteins from Human Multiple Myeloma U266 Cells by Proteomics

ObjectiveTo identify ubiquitinated proteins from complex human multiple myeloma (MM) U266 cells, a malignant disorder of differentiated human B cells.MethodsEmploying a globally proteomic strategy combining of immunoprecipitation, LC-MS/MS and SCX-LC-MS analysis to identified ubiquitination sites, which were identified by detecting signature peptides containing a GG-tag (114.1 Da) and an LRGG-tag (383.2 Da).ResultsIn total, 52 ubiquitinated proteins containing 73 ubiquitination sites of which 14 and 59 sites contained LRGG-tag and GG-tag were identified, respectively.ConclusionClassification analysis by of the proteins identified in the study based on the PANTHER showed that they were associated with multiple functional groups. This suggested the involvement of many endogenous proteins in the ubiquitination in MM.