@article{mbs:/content/journal/micro/10.1099/mic.0.000705, author = "Maarsingh, Jason D. and Haydel, Shelley E.", title = "Mycobacterium smegmatis PrrAB two-component system influences triacylglycerol accumulation during ammonium stress", journal= "Microbiology", year = "2018", volume = "164", number = "10", pages = "1276-1288", doi = "https://doi.org/10.1099/mic.0.000705", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.000705", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "triacylglycerol", keywords = "Mycobacteria", keywords = "two-component system", keywords = "lipidomics", abstract = "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.", }