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Updated: Jul 14, 2025

Single Cell Measurements of Vacuolar Rupture Caused by Intracellular Pathogens
Published on: June 12, 2013
Rab41-mediated ESCRT machinery repairs membrane rupture by a bacterial toxin in xenophagy
Takashi Nozawa1, Hirotaka Toh1, Junpei Iibushi1
1Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
Abstract:
Xenophagy, a type of selective autophagy, is a bactericidal membrane trafficking that targets cytosolic bacterial pathogens, but the membrane homeostatic system to cope with bacterial infection in xenophagy is not known. Here, we show that the endosomal sorting complexes required for transport (ESCRT) machinery is needed to maintain homeostasis of xenophagolysosomes damaged by a bacterial toxin, which is regulated through the TOM1L2-Rab41 pathway that recruits AAA-ATPase VPS4. We screened Rab GTPases and identified Rab41 as critical for maintaining the acidification of xenophagolysosomes. Confocal microscopy revealed that ESCRT components were recruited to the entire xenophagolysosome, and this recruitment was inhibited by intrabody expression against bacterial cytolysin, indicating that ESCRT targets xenophagolysosomes in response to a bacterial toxin. Rab41 translocates to damaged autophagic membranes via adaptor protein TOM1L2 and recruits VPS4 to complete ESCRT-mediated membrane repair in a unique GTPase-independent manner. Finally, we demonstrate that the TOM1L2-Rab41 pathway-mediated ESCRT is critical for the efficient clearance of bacteria through xenophagy.
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