TY - JOUR
T1 - Mycobacterium smegmatis prrab two-component system influences triacylglycerol accumulation during ammonium stress
AU - Maarsingh, Jason D.
AU - Haydel, Shelley
N1 - Funding Information:
This work was supported by a Potts Memorial Foundation grant FP3606 to SEH.
Publisher Copyright:
© 2018 The Authors.
PY - 2018/10
Y1 - 2018/10
N2 - 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.
AB - 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.
KW - Lipidomics
KW - Mycobacteria
KW - Triacylglycerol
KW - Two-component system
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U2 - 10.1099/mic.0.000705
DO - 10.1099/mic.0.000705
M3 - Article
C2 - 30084767
AN - SCOPUS:85055028071
SN - 1350-0872
VL - 164
SP - 1276
EP - 1288
JO - Microbiology (United Kingdom)
JF - Microbiology (United Kingdom)
IS - 10
M1 - 000705
ER -