ESCRT and autophagy cooperate to repair ESX-1-dependent damage to the Mycobacterium-containing vacuole

Abstract

AbstractPhagocytes capture invader microbes within the bactericidal phagosome. Some pathogens subvert killing by damaging and escaping from this compartment. To prevent and fight bacterial escape, cells contain and repair the membrane damage, or finally eliminate the cytosolic escapees. All eukaryotic cells engage highly conserved mechanisms to ensure integrity of membranes in a multitude of physiological and pathological situations, including the Endosomal Sorting Complex Required for Transport (ESCRT) and autophagy machineries. In Dictyostelium discoideum, recruitment of the ESCRT-III protein Snf7/Chmp4/Vps32 and the ATPase Vps4 to sites of membrane repair relies on the ESCRT-I component Tsg101 and occurs in absence of Ca2+. The ESX-1 dependent membrane perforations produced by the pathogen Mycobacterium marinum separately engage both ESCRT and autophagy. In absence of Tsg101, M. marinum escapes earlier to the cytosol, where it is restricted by xenophagy. We propose that ESCRT has an evolutionary conserved function in containing intracellular pathogens in intact compartments.