To determine whether Ubc9 auto-sumoylation facilitates a broad transition in substrate targeting that might be connected to the genome-wide changes of SUMO-chromatin association (Fig. 6), we compared SUMO-conjugated substrates between the WT and ubc9-RR strains expressing HF-Smt3 using affinity purification and mass spectrometry (Fig. 7 and Supplementary Data 4). Here, SUMO1 is linked to hydrops fetalis.