4-Octyl itaconate restricts STING activation by blocking its palmitoylation

Cell Rep. 2023 Sep 26;42(9):113040. doi: 10.1016/j.celrep.2023.113040. Epub 2023 Aug 24.


The cyclic guanosine monophosphate adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) axis plays a vital role in defending foreign pathogens and maintaining immune homeostasis. While substantial advances have been made in understanding the metabolic changes that occur during macrophage activation, little is known about how these metabolic changes affect the cGAS-STING axis. In this study, we identify that 4-octyl itaconate (4-OI), a derivative of itaconate, inhibits the activation of cGAS-STING. Furthermore, we show that 4-OI inhibits cGAS-STING-related antiviral immune responses and autoimmune inflammation. However, we find that endogenous itaconate does not affect cGAS-STING activation, indicating that 4-OI and itaconate function differently. Mechanistically, we find that 4-OI directly alkylates STING at Cys91, blocking STING palmitoylation and oligomerization. The alkylation of STING by 4-OI represents another type of post-translational modifications (PTMs) of STING. Our findings reveal a mechanism by which cGAS-STING function is regulated through 4-OI alkylation and provide insights into the crosstalk between different kinds of PTMs.

Keywords: 4-OI; CP: Immunology; CP: Molecular biology; PTM; alkylation; cGAS-STING; palmitoylation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Lipoylation*
  • Nucleotidyltransferases* / metabolism
  • Succinates / pharmacology


  • itaconic acid
  • 4-octyl itaconate
  • Nucleotidyltransferases
  • Succinates