Enables ubiquitin binding activity. Involved in several processes, including cellular response to butyrate; cellular response to interleukin-11; and response to ischemia. Located in several cellular components, including myofibril; perikaryon; and postsynaptic density membrane. Part of proteasome complex. Biomarker of Alzheimer's disease and transient cerebral ischemia. Human ortholog(s) of this gene implicated in Charcot-Marie-Tooth disease axonal type 2F; distal hereditary motor neuropathy type 2B; pancreatic cancer; and sarcoma. Orthologous to human HSPB1 (heat shock protein family B (small) member 1). [provided by Alliance of Genome Resources, Apr 2022]