Contributes to the regulation of transcriptional activation of NF-kappa-B target genes. In the cytoplasm, inhibits the nuclear translocation of the NF-kappa-B p50 subunit. In the nucleus, acts as transcriptional activator that promotes transcription of NF-kappa-B target genes. Contributes to the regulation of cell proliferation (By similarity).
Subcellular locations: Nucleus, Cytoplasm, Cytoplasm, Perinuclear region
Ubiquitination via 'Lys-63'-linked ubiquitin chains is required for nuclear accumulation.