Project description:In this study, we describe an antibody-based approach to enrich ubiquitinated peptides from vegetative tissues for detection via peptide mass spectrometry. This enrichment method can be coupled with isobaric labeling to enable quantification from up to 18-multiplexed samples. This approach identified 19,740 ubiquitinated lysine sites arising from 5,936 proteins in Arabidopsis primary roots, seedlings and rosette leaves. Gene Ontology analysis indicated that ubiquitinated proteins are associated with numerous biological processes including hormone signaling, plant defense, protein homeostasis, and metabolism. Proteins with altered abundance and ubiquitination state in roots upon bortezomib treatment included transporters, adaptors, and transcription factors.
