Bacterial secretion systems: Networks of pathogenic regulation and adaptation in mycobacteria and beyond

Protein transport is essential for bacterial physiology General secretion systems, including the Sec and twin arginine translocation (Tat) systems, are universal in bacteria. [...]WXG proteins associated with T7SS are often required for the secretion of other substrates [11,23–26]. At least 2 ESX-1–associated transcription factors control substrate gene expression in response to the presence or absence of a protein transporter in the cytoplasmic membrane [54–58]. [...]the ESX-1 system functions in the phagosome to promote cytoplasmic access for pathogenic mycobacteria [64]. Since the ESX-1 system controls gene expression, this T7SS may indeed serve to sense and respond to cytoplasmic exposure [54,55,57].