Subunit of the 26S proteasome which plays a role in ubiquitin-dependent proteolysis. Has an essential role in oogenesis and larval growth. Required for intestinal function and default lifespan. Part of the 26S proteasome. Diffuse in cytoplasm. Expressed in intestinal epithelium and head neurons. Expressed in larval and adult stages. Embryonic lethality, growth defects, larval arrest, reduced lifespan, and sterility. Belongs to the DSS1/SEM1 family.