Autophagy and endosomal trafficking inhibition by Vibrio cholerae MARTX toxin phosphatidylinositol-3-phosphate-specific phospholipase A1 activity

作者：Agarwal Shivani; Kim Hyunjin; Chan Robin B; Agarwal Shivangi; Williamson Rebecca; Cho Wonhwa; Paolo Gilbert D; Satchell Karla J F^*

来源：Nature Communications, 2015, 6(1): 8745.

DOI：10.1038/ncomms9745

Vibrio cholerae, responsible for acute gastroenteritis secretes a large multifunctional-autoprocessing repeat-in-toxin (MARTX) toxin linked to evasion of host immune system, facilitating colonization of small intestine. Unlike other effector domains of the multifunctional toxin that target cytoskeleton, the function of alpha-beta hydrolase (ABH) remained elusive. This study demonstrates that ABH is an esterase/lipase with catalytic Ser-His-Asp triad. ABH binds with high affinity to phosphatidylinositol-3-phosphate (PtdIns3P) and cleaves the fatty acid in PtdIns3P at the sn1 position in vitro making it the first PtdIns3P-specific phospholipase A1 (PLA1). Expression of ABH in vivo reduces intracellular PtdIns3P levels and its PtdIns3P-specific PLA1 activity blocks endosomal and autophagic pathways. In accordance with recent studies acknowledging the potential of extracellular pathogens to evade or exploit autophagy to prevent their clearance and facilitate survival, this is the first report highlighting the role of ABH in inhibiting autophagy and endosomal trafficking induced by extracellular V. cholerae.

• 出版日期2015-10
• 单位西北大学