[Isoform 1]: E3 ubiquitin ligase which accepts ubiquitin from specific E2 ubiquitin-conjugating enzymes, and then transfers it to substrates promoting their ubiquitination (PubMed:34998453). Plays a role in the regulation of antiviral responses by promoting the degradation of TRAF3, TLR4 and TLR9 (PubMed:15107846, PubMed:19893624). In turn, down-regulates NF-kappa-B and IRF3 activation as well as beta interferon production. Also participates in the regulation of autophagy by ubiquitinating BECN1 leading to its degradation and autophagy inhibition (PubMed:25484083). Plays a role in ARC-dependent synaptic plasticity by mediating ARC ubiquitination resulting in its rapid proteasomal degradation (PubMed:24945773). Plays aso an essential role in spermatogenesis and male fertility (By similarity). Mechanistically, regulates meiosis by promoting the degradation of PRKACB through the ubiquitin-mediated lysosome pathway (By similarity). Modulates the gonadotropin-releasing hormone signal pathway by affecting the stability of STAU2 that is required for the microtubule-dependent transport of neuronal RNA from the cell body to the dendrite (By similarity). {ECO:0000250|UniProtKB:P58283, ECO:0000269|PubMed:15107846, ECO:0000269|PubMed:19893624, ECO:0000269|PubMed:24945773, ECO:0000269|PubMed:25484083, ECO:0000269|PubMed:34998453}. [Isoform 3]: Inhibits TNF and IL-1 mediated activation of NF- kappa-B. Promotes TNF and RIP mediated apoptosis. . This is the function of Ensembl gene identifier ENSG00000011275 (RNF216, ring finger protein 216).