%0 Journal Article %A Maarsingh, Jason D. %A Haydel, Shelley E. %T Mycobacterium smegmatis PrrAB two-component system influences triacylglycerol accumulation during ammonium stress %D 2018 %J Microbiology, %V 164 %N 10 %P 1276-1288 %@ 1465-2080 %R https://doi.org/10.1099/mic.0.000705 %K triacylglycerol %K Mycobacteria %K two-component system %K lipidomics %I Microbiology Society, %X 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. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.000705