Mycobacterium smegmatis prrab two-component system influences triacylglycerol accumulation during ammonium stress

Jason D. Maarsingh, Shelley Haydel

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


The PrrAB two-component system is conserved across all sequenced mycobacterial species and is essential for viability in Mycobacterium tuberculosis, thus making it a promising drug target. The prrAB operon was successfully deleted in nonpathogenic Mycobacterium smegmatis, and the ∆prrAB mutant strain exhibited clumping in ammonium-limited medium and significantly reduced growth during ammonium and hypoxic stress. To assess the influence of M. tuberculosis PrrA overexpression, we constructed a recombinant M. smegmatis ∆prrAB mutant strain which overexpresses M. tuberculosis prrA. M. smegmatis prrAB and M. tuberculosis prrA complemented the M. smegmatis ∆prrAB deletion mutant in Middlebrook M7H9 and ammonium-limited media and during hypoxic and ammonium stress. Based on quantitative untargeted mass spectrometry-based lipidomics, triacylglycerol lipid species were significantly upregulated in the ∆prrAB mutant strain compared to the wild-type when cultured in ammonium-limited medium, revealing that M. smegmatis PrrAB influences triacylglycerol levels during ammonium stress. These results were qualitatively corroborated by thin-layer chromatography. Furthermore, the ∆prrAB mutant significantly upregulated expression of several genes (glpK, GPAT, WS/DGAT, accA3, accD4, accD6 and Ag85C) that participate in triacylglycerol and lipid biosynthetic pathways, thus corroborating the lipidomics analyses.

Original languageEnglish (US)
Article number000705
Pages (from-to)1276-1288
Number of pages13
JournalMicrobiology (United Kingdom)
Issue number10
StatePublished - Oct 2018


  • Lipidomics
  • Mycobacteria
  • Triacylglycerol
  • Two-component system

ASJC Scopus subject areas

  • Microbiology


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