Fig. 1.

Model of SUMOylation. Initially, SUMO is an inactive precursor. SENPs, and sentrin-specific proteases catalyze and expose the diglycine (GG) motif of SUMO at the C-terminus. Then, through E1, E2, and E3 enzymes, SUMO is conjugated to the lysine (K) residue in the substrate that is often found in a consensus sequence. This modification modulates downstream biological functions of target proteins, such as protein–protein interactions and transcriptional regulation. SUMO attachment is reversible and removed from the substrate by SENPs