Small ubiquitin-related modifier 4 (SUMO4)

Ubiquitin-like protein which can be covalently attached to target lysines as a monomer. Does not seem to be involved in protein degradation and might regulate protein subcellular localization, stability or action.

Upon oxidative stress, conjugates to different anti-oxidant enzymes, chaperones, and anxiety defense proteins. May also conjugate to NFKBIA, TFAP2A and FOS, negatively regulating their transcriptional activity, and to NR3C1, positively regulating its transcriptional activity.