Essential component of a ubiquitin-editing protein complex, comprising also TNFAIP3, ITCH and TAX1BP1, that ensures the transient nature of inflammatory signaling pathways. Promotes the association of TNFAIP3 to RIPK1 after TNF stimulation. TNFAIP3 deubiquitinates 'Lys-63' polyubiquitin chains on RIPK1 and catalyzes the formation of 'Lys-48'-polyubiquitin chains. This leads to RIPK1 proteasomal degradation and consequently termination of the TNF- or LPS-mediated activation of NF-kappa-B. Recruits STAMBP to the E3 ubiquitin-ligase SMURF2 for ubiquitination, leading to its degradation by the 26S proteasome.
Subcellular locations: Early endosome, Recycling endosome, Cytoplasm, Nucleus
Predominantly cytoplasmic, when unphosphorylated, and nuclear, when phosphorylated by PKB/AKT1.
Expressed at low levels in the lung, liver, kidney, pancreas, spleen, prostate, thymus, ovary, small intestine, colon, and peripheral blood lymphocytes, and, at intermediate levels, in the testis, heart, brain and placenta. Highest expression in the skeletal muscle. In the brain, expressed at different levels in several regions: high levels in the amygdala, moderate in the hippocampus and thalamus, low in the caudate and extremely low levels in the corpus callosum (at protein level). Restricted to neurons, enriched in somatodendritic compartments and excluded from white matter (at protein level). In substantia nigra, present in cell bodies and processes of dopaminergic and nondopaminergic cells (at protein level). In Parkinson disease, sequestered in Lewy bodies and neurites. Overexpressed in breast cancer cells, but not detected in the surrounding stroma and weakly, if at all, in normal breast epithelial cells (at protein level). Also expressed in several tumor cell lines.