CIKS/DDX3X interaction controls the stability of the Zc3h12a mRNA induced by IL-17.

IL-17 is a proinflammatory cytokine that promotes the expression of different cytokines and chemokines via the induction of gene transcription and the posttranscriptional stabilization of mRNAs. In this study, we show that IL-17 increases the half-life of the Zc3h12a mRNA via interaction of the adaptor protein CIKS with the DEAD box protein DDX3X. IL-17 stimulation promotes the formation of a complex between CIKS and DDX3X, and this interaction requires the helicase domain of DDX3X but not its ATPase activity. DDX3X knockdown decreases the IL-17-induced stability of Zc3h12a without affecting the stability of other mRNAs. IKKε, TNFR-associated factor 2, and TNFR-associated factor 5 were also required to mediate the IL-17-induced Zc3h12a stabilization. DDX3X directly binds the Zc3h12a mRNA after IL-17 stimulation. Collectively, our findings define a novel, IL-17-dependent mechanism regulating the stabilization of a selected mRNA.