Enables SUMO-specific isopeptidase activity. Acts upstream of or within negative regulation of proteasomal ubiquitin-dependent protein catabolic process; protein desumoylation; and regulation of definitive erythrocyte differentiation. Predicted to be located in focal adhesion; nuclear membrane; and nucleoplasm. Predicted to be active in nucleus. Is expressed in embryo and heart. Used to study type 1 diabetes mellitus. Orthologous to human SENP1 (SUMO specific peptidase 1). [provided by Alliance of Genome Resources, Apr 2022]