TRIM22 can activate the noncanonical NF-κB pathway by affecting IKKα

Tripartite motif 22 (TRIM22) is involved in various cellular processes. It has been reported that TRIM22 can activate nuclear factor-B (NF-B) pathway, but the precise mechanism remains unclear. In this study, we explored the exact role of TRIM22 in activating the NF-B pathway. Different to tumor necrosis factor- (TNF-) induction, we found that the overexpression of TRIM22 could induce the processing of p100 to p52 in HEK293T cells. Furthermore, based on the results of co-immunoprecipitation and co-localization experiments, we demonstrated that TRIM22 could interact with IB kinase (IKK) but not IKK and could increase the level and phosphorylation of IKK through its really interesting new gene (RING) and spla-ryanodine receptor (SPRY) domains. These results suggest that TRIM22 is able to activate the noncanonical but not the canonical NF-B pathway by activating IKK. This finding will aid our understanding of the biological function of TRIM22.