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

Abstract

Increasing evidence demonstrates that lysine acetylation is involved in Mycobacterium tuberculosis (Mtb) virulence and pathogenesis. However, previous investigations in Mtb have only monitored acetylation at lysine residues using selected reference strains. We analyzed the global Nε- and O-acetylation of 3 Mtb isolates; 2 lineage 7 clinical isolates and the lineage 4 H37Rv reference strain. Quantitative acetylome analysis resulted in identification of 2490 class-I acetylation sites, among them 2349 O-acetylation and 141 Nε-acetylation sites, derived from 953 unique proteins. Mtb O-acetylation was thereby significantly more abundant than Nε-acetylation. The acetylated proteins were found to be involved in central metabolism, translation, stress responses and antimicrobial drug resistance. Notably, 261 acetylation sites on 165 proteins were differentially regulated between lineage 7 and lineage 4 strains. A total of 257 acetylation sites on 161 proteins were hypoacetylated in lineage 7 strains. These proteins are involved in Mtb growth, virulence, bioenergetics, host-pathogen interaction and stress responses. This study provides the first global analysis of O-acetylated proteins in Mtb. This quantitative acetylome data expand the current understanding regarding the nature and diversity of acetylated proteins in Mtb, and opens a new avenue of research for exploring the role of protein acetylation in Mtb physiology.

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