Enables ubiquitin binding activity. Acts upstream of or within several processes, including macroautophagy; osteoblast differentiation; and ubiquitin-dependent protein catabolic process. Predicted to be located in cytosol. Predicted to be active in autophagosome and nucleus. Is expressed in several structures, including 1st branchial arch; facial prominence; limb mesenchyme; nervous system; and otocyst. Orthologous to human TP53INP2 (tumor protein p53 inducible nuclear protein 2). [provided by Alliance of Genome Resources, Apr 2022]