Double trouble: Bacillus depends on a functional Tat machinery to avoid severe oxidative stress and starvation upon entry into a NaCl-depleted environment

Bimal Prajapati, Margarita Bernal-Cabas, Marina Lopez-Alvarez, Marc Schaffer, Jurgen Bartel, Hermann Rath, Leif Steil, Dorte Becher, Uwe Volker, Ulrike Mader*, Jan Maarten van Dijl*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

The widely conserved twin-arginine translocases (Tat) allow the transport of fully folded cofactor-containing proteins across biological membranes. In doing so, these translocases serve different biological functions ranging from energy conversion to cell division. In the Gram-positive soil bacterium Bacillus subtilis, the Tat machinery is essential for effective growth in media lacking iron or NaCl. It was previously shown that this phenomenon relates to the Tat-dependent export of the heme-containing peroxidase EfeB, which converts Fe2+ to Fe3+ at the expense of hydrogen peroxide. However, the reasons why the majority of tat mutant bacteria perish upon dilution in NaCl-deprived medium and how, after several hours, a sub-population adapts to this condition was unknown. Here we show that, upon growth in the absence of NaCl, the bacteria face two major problems, namely severe oxidative stress at the membrane and starvation leading to death. The tat mutant cells can overcome these challenges if they are fed with arginine, which implies that severe arginine depletion is a major cause of death and resumed arginine synthesis permits their survival. Altogether, our findings show that the Tat system of B. subtilis is needed to preclude severe oxidative stress and starvation upon sudden drops in the environmental Na+ concentration as caused by flooding or rain.

Original languageEnglish
Article number118914
Number of pages14
JournalBiochimica et Biophysica Acta (BBA) - Molecular Cell Research
Volume1868
Issue number2
DOIs
Publication statusPublished - Feb-2021

Keywords

  • Twin-arginine translocation
  • Bacillus subtilis
  • Protein secretion
  • Oxidative stress
  • EfeB
  • QcrA
  • SUBTILIS GENE-EXPRESSION
  • PROTEIN SECRETION
  • IN-VITRO
  • RNA SR1
  • TRANSCRIPTOME
  • RESISTANCE
  • TRANSPORT
  • REPRESSOR
  • OPERON
  • MEMBRANE

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