negative regulation of protein sumoylation
Any process that stops, prevents, or reduces the frequency, rate or extent of the addition of SUMO groups to a protein.
GO:0033233
regulation of protein sumoylation
is_a
GO:1903321
negative regulation of protein modification by small protein conjugation or removal
is_a
GO:0016925
protein sumoylation
negatively_regulates
negative regulation of sumoylation
exact