Involved in protein degradation via the ubiquitin-proteasome system. May act by anchoring ubiquitinated proteins to the proteasome. Plays a role in ubiquitin-mediated protein degradation during muscle atrophy. Plays a role in the regulation of NF-kappa-B activation and apoptosis. Inhibits NF-kappa-B activation triggered by overexpression of RIPK1 and TRAF6 but not of RELA. Inhibits also tumor necrosis factor (TNF), IL-1 and TLR4-induced NF-kappa-B activation in a dose-dependent manner. Overexpression sensitizes cells to TNF-induced apoptosis. Is a potent inhibitory factor for osteoclast differentiation.
Subcellular locations: Cytoplasm
Highly expressed in skeletal muscle. Expressed in fetal cochlea. Also expressed in infant brain, fetal heart, pancreatic islet, melanocyte, pineal gland, placenta, corneal stroma, and parathyroid tumor. Weakly expressed or undetectable in adult brain, heart, colon, thymus, spleen, kidney, liver, small intestine, placenta, lung and peripheral blood leukocytes. Expressed in rhabdomyosarcoma RD cells (at protein level).