Proteins bearing oxidation-induced carbonyl groups are not preferentially ubiquitinated

► Oxidized proteins were analyzed in a cell model of oxidative stress induced by hydrogen peroxide and UV-A. ► Protein oxidation was accompanied by an increase in ubiquitination. ► However, oxidized proteins were not preferentially ubiquitinated. ► Separation of ubiquitinated and non-ubiquitinated proteins revealed also, that oxidized proteins are not preferentially ubiquitinated.