Interrogation of the Ubiquitinated Proteome of Exosomes Shed by Myeloid-derived Suppressor Cells

摘要

Tandem mass spectrometry coupled with immunoprecipitation has successfully been used to identify 15 ubiquitinated proteins in MDSCderived exosomes with high reliability. Of this total, 13 proteins have not previously been reported as ubiquitinated. To date, the number of ubiquitinated proteins is less than 5% of the total number identied in an exosome lysate. It seems unlikely that ubiquitination is required for every protein sorted into exosomes.