E3 ubiquitin-protein ligase that plays a role in the regulation of inflammatory response. Mechanistically, mediates the 'Lys-48'-linked polyubiquitination of TAB2, a regulatory protein of the kinase TAK1, leading to its degradation via the proteasomal pathway and inhibition of the TLR-mediated inflammatory immune response. May act as a transcriptional repressor in mitogen-activated protein kinase signaling pathway