Pseudomonas aeruginosa T6SS-mediated molybdate transport contributes to bacterial competition during anaerobiosis

Cell Rep. 2021 Apr 13;35(2):108957. doi: 10.1016/j.celrep.2021.108957.

Abstract

Type VI secretion system (T6SS) is widely distributed in Gram-negative bacteria and functions as a versatile protein export machinery that translocates effectors into eukaryotic or prokaryotic target cells. Growing evidence indicates that T6SS can deliver several effectors to promote bacterial survival in harmful environments through metal ion acquisition. Here, we report that the Pseudomonas aeruginosa H2-T6SS mediates molybdate (MoO42-) acquisition by secretion of a molybdate-binding protein, ModA. The expression of H2-T6SS genes is activated by the master regulator Anr and anaerobiosis. We also identified a ModA-binding protein, IcmP, an insulin-cleaving metalloproteinase outer membrane protein. The T6SS-ModA-IcmP system provides P. aeruginosa with a growth advantage in bacterial competition under anaerobic conditions and plays an important role in bacterial virulence. Overall, this study clarifies the role of T6SS in secretion of an anion-binding protein, emphasizing the fundamental importance of this bacterium using T6SS-mediated molybdate uptake to adapt to complex environmental conditions.

Keywords: Anr regulator; Pseudomonas aeruginosa; T6SS; anaerobic condition; molybdate acquisition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anaerobiosis / genetics*
  • Animals
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Female
  • Gene Expression Regulation, Bacterial*
  • Ion Transport
  • Metalloendopeptidases / genetics
  • Metalloendopeptidases / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Microbial Interactions / genetics
  • Microbial Viability
  • Molybdenum / metabolism*
  • Pseudomonas Infections / microbiology
  • Pseudomonas Infections / mortality
  • Pseudomonas Infections / pathology
  • Pseudomonas aeruginosa / genetics*
  • Pseudomonas aeruginosa / metabolism
  • Pseudomonas aeruginosa / pathogenicity
  • Survival Analysis
  • Trans-Activators / genetics
  • Trans-Activators / metabolism
  • Type VI Secretion Systems / genetics
  • Type VI Secretion Systems / metabolism
  • Virulence
  • Virulence Factors / genetics*
  • Virulence Factors / metabolism

Substances

  • Bacterial Proteins
  • Carrier Proteins
  • Trans-Activators
  • Type VI Secretion Systems
  • Virulence Factors
  • molybdate
  • ANR protein, Pseudomonas aeruginosa
  • Molybdenum
  • Metalloendopeptidases
  • insulin-cleaving membrane proteinase