The research team led by Prof. Chu Wang at the College of Chemistry and Molecular Engineering, Peking-Tsinghua Center for Life Sciences,Peking University, and Prof. Suwei Dong at School of Pharmaceutical Sciences, Peking University, has recently published a research article titled “Discovery of Itaconate-Mediated Lysine Acylation” in Journal of the American Chemical Society. In this work, the authors discovered a new type of protein post-translational modification (PTM) called itaconylation, which opens up new areas for studying how itaconate participates in immunoregulation.
Itaconate is recently discovered as an important anti-microbial and immunoregulatory metabolite generated in macrophages stimulated by pathogens or lipopolysaccharides (LPS). Owing to the electrophilic α,β-unsaturated carboxylic acid structure, itaconate could covalently modify key cysteine residues on proteins, resulting in “itaconation”. Previously, Chu Wang’s research team reported the global profiling of itaconation sites in both macrophages and pathogens (Nat. Chem.Biol. 2019, J. Am. Chem. Soc. 2020, Chem. Sci. 2021). Recent studies suggested that itaconate has other regulatory mechanisms. But until now, no other form of modification mediated by itaconate has been reported.
When the author performed a profiling of the succinylation proteome in itaconate-treated RAW264.7 macrophages, they unexpectedly identified a previously unknown modification after analyzing the resulting LC-MS/MS data in the open search mode. The new modification had a 112.0162 Da mass shift, which corresponded to the acylation form of itaconate. They then set up an LC-MS/MS assay for the detection of its predicted precursor metabolite itaconyl-CoA, and found that both itaconylation and itaconyl-CoA underwent significantly upregulation upon LPS stimulation. By quantitative proteomics, the author identified itaconylation sites on multiple functional proteins, including glycolytic enzymes and histones. The structure of itaconylation was further confirmed by a coelution experiment with synthetic isotopically labeled standard peptides.
In conclusion, this work reported the discovery and verification of a new itaconate-derived modification, lysine itaconylation, which will open opportunities for in-depth functional studies to reveal the novel biological roles of itaconate in the future.
Fig. 1 Itaconateis metabolized to itaconyl-CoA and forms itaconylation on lysine residues.
Prof. Chu Wang and Prof. Suwei Dongare the corresponding authors of this paper. Dongyang Liu, Dr. Weidi Xiao from Chu Wang’s research group at College of Chemistry and Molecular Engineering, and Haoting Li from School of Pharmaceutical Sciences, Peking University, are the co-first authors of this paper. Collaborators include Dr. Yanling Zhang, Dr. Shouli Yuan and Chengxi Li. This work was supported by the National Key R&D Program of China, the National Natural Science Foundation of China and Beijing National Laboratory for Molecular Sciences.
Original link for the paper: https://pubs.acs.org/doi/10.1021/jacs.3c02332
