Phosphatidic acid-mediated binding and mammalian cell internalization of the Vibrio cholerae cytotoxin MakA

PLoS Pathog. 2021 Mar 18;17(3):e1009414. doi: 10.1371/journal.ppat.1009414. eCollection 2021 Mar.

Abstract

Vibrio cholerae is a noninvasive intestinal pathogen extensively studied as the causative agent of the human disease cholera. Our recent work identified MakA as a potent virulence factor of V. cholerae in both Caenorhabditis elegans and zebrafish, prompting us to investigate the potential contribution of MakA to pathogenesis also in mammalian hosts. In this study, we demonstrate that the MakA protein could induce autophagy and cytotoxicity of target cells. In addition, we observed that phosphatidic acid (PA)-mediated MakA-binding to the host cell plasma membranes promoted macropinocytosis resulting in the formation of an endomembrane-rich aggregate and vacuolation in intoxicated cells that lead to induction of autophagy and dysfunction of intracellular organelles. Moreover, we functionally characterized the molecular basis of the MakA interaction with PA and identified that the N-terminal domain of MakA is required for its binding to PA and thereby for cell toxicity. Furthermore, we observed that the ΔmakA mutant outcompeted the wild-type V. cholerae strain A1552 in the adult mouse infection model. Based on the findings revealing mechanistic insights into the dynamic process of MakA-induced autophagy and cytotoxicity we discuss the potential role played by the MakA protein during late stages of cholera infection as an anti-colonization factor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / metabolism*
  • Cell Line
  • Cholera / metabolism
  • Cytotoxins / metabolism*
  • Humans
  • Mice
  • Phosphatidic Acids / metabolism*
  • Vibrio cholerae / pathogenicity*
  • Virulence Factors / metabolism*
  • Virus Internalization

Substances

  • Bacterial Proteins
  • Cytotoxins
  • Phosphatidic Acids
  • Virulence Factors

Grants and funding

This work was supported by grants from the Swedish Research Council (2018-02914 to S.N.W.; 2016-05009 to K.P; 2019-01720 to B.E.U.), The Swedish Cancer Society (2017-419 to S.N.W.), The Kempe Foundations (JCK-1728 to S.N.W.; SMK-1756.2 and SMK-1553 to K.P.; JCK-1724 to B.E.U), the Natural Science Foundation of Jiangsu Province (BK20191314 to H.W.), and the Faculty of Medicine at Umeå University (Strategic Research Grant 2019-2021 to S.N.W.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.