First Succinyl-Proteome Profiling of Extensively Drug-Resistant Mycobacterium tuberculosis Revealed Involvement of Succinylation in Cellular Physiology

Abstract

Protein lysine succinylation, an emerging protein post-translational modification widespread among eukaryotic and prokaryotic cells, represents an important regulator of cellular processes. However, the extent and function of lysine succinylation in Mycobacterium tuberculosis, especially extensively drug-resistant strain, remain elusive. Combining protein/peptide prefractionation, immunoaffinity enrichment, and LC-MS/MS analysis, a total of 686 succinylated proteins and 1739 succinylation sites of M. tuberculosis were identified, representing the first global profiling of M. tuberculosis lysine succinylation. The identified succinylated proteins are involved in a variety of cellular functions such as metabolic processes, transcription, translation, and stress responses and exhibit different subcellular localization via GO, protein interaction network, and other bioinformatic analysis. Notably, proteins involved in protein biosynthesis and carbon metabolism are preferred targets of lysine succinylation. Moreover, two prevalent sequence patterns: EK(suc) and K*****K(suc), can be found around the succinylation sites. There are 109 lysine-succinylated homologues in E. coli, suggesting highly conserved succinylated proteins. Succinylation was found to occur at the active sites predicted by Prosite signature including Rv0946c, indicating that lysine succinylation may affect their activities. There is extensive overlapping between acetylation sites and succinylation sites in M. tuberculosis. Many M. tuberculosis metabolic enzymes and antibiotic resistance proteins were succinylated. This study provides a basis for further characterization of the pathophysiological role of lysine succinylation in M. tuberculosis.

Nε- and O-Acetylation in Mycobacterium tuberculosis Lineage 7 and Lineage 4 Strains: Proteins Involved in Bioenergetics, Virulence, and Antimicrobial Resistance Are Acetylated

“…These heavily acetylated proteins are known to be involved in stress responses, corroborating previous data indicating a role for protein acetylation in stress adaptation in Mtb and other bacteria. 17,48,49 …”

“…In accordance with our finding, mutagenesis of the active site K221 of the pyruvate kinase was shown to reduce the activity of this enzyme by a factor of 10 4 to 10 5 in Bacillus stearothermophilus . 65 Even though the effect of O-acetylation on bacterial enzyme activity has not been investigated to date, it is possible that direct acetylation of such active site residues may modulate, abolish, or induce the enzyme activity 49 or interfere with the phosphorylation event. 53 …”

“…Despite the variations in the methods used and the acetylated residues analyzed, this finding was in agreement with a previous study on lysine acetylation and succinylation. 15,17,49 …”

“…49 PTMs may alter the net charge on the protein, conformation, interaction, and activity, thereby modulating the bacterial response to drugs. Acetylation of kinase substrates might alter the signaling pathways that lead to drug resistance/sensitivity.…”

Opinion Prediction of protein Post-Translational Modification sites: An overview

“…PTM is a common biological mechanism of both eukaryotic and prokaryotic organisms, which regulates the protein functions, the proteolytic cleavage of regulatory subunits or the degradation of entire proteins and affects all aspects of cellular life. The PTM of a protein can also determine the cell signaling state, turnover, localization, and interactions with other proteins [2]. Therefore, the analysis of proteins and their PTMs are particularly important for the study of heart disease, cancer, neurodegenerative diseases and diabetes [3,4].…”