Predicted to enable proteasome binding activity; protein heterodimerization activity; and protein homodimerization activity. Predicted to be involved in negative regulation of proteasomal protein catabolic process and ubiquitin-dependent protein catabolic process. Predicted to be located in cytosol; endoplasmic reticulum; and perinuclear region of cytoplasm. Predicted to be part of proteasome complex. Is expressed in several structures, including alimentary system; eye; genitourinary system; lung; and nervous system. Orthologous to human PSMF1 (proteasome inhibitor subunit 1). [provided by Alliance of Genome Resources, Apr 2022]