Fig. 2
Distribution of the quantified ubiquitylated peptides of human origin. a A total of 249 ubiquitylated peptides of human origin were quantified with a mean relative abundance of -0.004. For each ubiquitylated peptide, the average iTRAQ reporter ion intensity values of the luminal samples (116 and 117 labels) were divided by the average iTRAQ reporter ion intensity values of the basal samples (114 and 115) and log2-transformed. b Number of ubiquitylated proteins vs. the number of ubiquitylation sites per protein