Frequently arising ESX-1-associated phase variants influence <i>Mycobacterium tuberculosis</i> fitness in the presence of host and antibiotic pressures.

ABSTRACT: Mycobacterium tuberculosis (Mtb) exhibits an impressive ability to adapt to rapidly changing environments, despite its genome's apparent stability. Recently, phase variation through indel formation in homopolymeric tracts (HT) has emerged as a potentially important mechanism promoting adaptation in Mtb. This study examines the impact of common phase variants associated with the ESX-1 type VII secretion system, focusing on a highly variable HT upstream of the ESX-1 regulatory factor, espR. By engineering this frequently observed indel into an isogenic background, we demonstrate that a single nucleotide insertion in the espR 5'UTR causes post-transcriptional upregulation of EspR protein abundance and corresponding alterations in the EspR regulon. Consequently, this mutat

SUBMITTER: Luna MJ 

PROVIDER: S-EPMC11898584 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature