E3 ubiquitin ligase that plays a crucial role in the activation of the IKBKE-dependent branch of the type I interferon signaling pathway (, ). In concert with the ubiquitin-conjugating E2 enzyme UBE2K, synthesizes unanchored 'Lys-48'-linked polyubiquitin chains that promote the oligomerization and autophosphorylation of IKBKE leading to stimulation of an antiviral response . Ubiquitinates also MYC and inhibits its transcription activation activity, maintaining the pluripotency of embryonic stem cells (By similarity). Promotes the association of unanchored 'Lys-48'-polyubiquitin chains with DHX16 leading to enhanced RIGI-mediated innate antiviral immune response .
(Microbial infection) Ubiquitinates ebolavirus protein VP35 leading to enhanced viral transcriptase activity.
Subcellular locations: Cytoplasm