A development of an Artificial SUMO Ligase (ASUL) to increase the ability of Ubc9 to interact with the SUMO target protein, therefore increasing the rate of SUMOylation of the target and a net increase in the total amount of SUMOylated target protein in the cell is described herein. The method of the present invention involves the creation of a protein fusion between a protein domain known to interact with the target protein to be SUMOylated (ID) and the SUMO conjugating enzyme Ubc9. Compositions and methods involving an ASUL comprising a fusion of the N-terminal domain of influenza A virus non-structural protein (NS1) and Ubc9 is also described.
