HDAC4 SUMOylates NR1H3 with SUMO2,3 (Ghisletti et al. 2007). SUMOylation is enhanced when NR1H3 binds specific oxysterols. SUMOylation causes NR1H3 to recruit the NCOR repressor and act as a transrepressor at promoters such as iNOS.
SUMO transferase activity of HDAC4 [nucleoplasm]