Characterization of key enzymes involved in triacylglycerol biosynthesis in mycobacteria

Fecha

2021-06-24

Título de la revista

ISSN de la revista

Título del volumen

Editor

Scientific Reports
Resumen
Phosphatidic acid phosphatase (PAP) catalyzes the dephosphorylation of phosphatidic acid (PA) yielding diacylglycerol (DAG), the lipid precursor for triacylglycerol (TAG) biosynthesis. PAP activity has a key role in the regulation of PA flux towards TAG or glycerophospholipid synthesis. In this work we have characterized two Mycobacterium smegmatis genes encoding for functional PAP proteins. Disruption of both genes provoked a sharp reduction in de novo TAG biosynthesis in early growth phase cultures under stress conditions. In vivo labeling experiments demonstrated that TAG biosynthesis was restored in the ∆PAP mutant when bacteria reached exponential growth phase, with a concomitant reduction of phospholipid synthesis. In addition, comparative lipidomic analysis showed that the ∆PAP strain had increased levels of odd chain fatty acids esterified into TAGs, suggesting that the absence of PAP activity triggered other rearrangements of lipid metabolism, like phospholipid recycling, in order to maintain the wild type levels of TAG. Finally, the lipid changes observed in the ∆PAP mutant led to defective biofilm formation. Understanding the interaction between TAG synthesis and the lipid composition of mycobacterial cell envelope is a key step to better understand how lipid homeostasis is regulated during Mycobacterium tuberculosis infection.

Palabras clave

Escherichia Coli, Lipid Metabolism, Mycobacterium Smegmatis, Phosphatidate Phosphatase, Phosphatidic Acids, Phylogeny, Triglycerides

Citación