Exogenous Fatty Acids Remodel Staphylococcus aureus Lipid Composition through Fatty Acid Kinase
| Autor: | Zachary R. DeMars, Vineet K. Singh, Jeffrey L. Bose |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Staphylococcus aureus
Cellular respiration Phospholipid Biology medicine.disease_cause Microbiology Mice 03 medical and health sciences chemistry.chemical_compound Bacterial Proteins medicine Membrane fluidity Animals Molecular Biology Fatty acid synthesis Skin 030304 developmental biology chemistry.chemical_classification 0303 health sciences 030306 microbiology Fatty Acids Phosphotransferases Fatty acid Staphylococcal Infections Lipid Metabolism biology.organism_classification Lipids Mice Inbred C57BL Oleic acid chemistry Biochemistry Bacteria Oleic Acid Research Article |
| Zdroj: | J Bacteriol |
| ISSN: | 1098-5530 0021-9193 |
| Popis: | Staphylococcus aureus can utilize exogenous fatty acids for phospholipid synthesis. The fatty acid kinase FakA is essential for this utilization by phosphorylating exogenous fatty acids for incorporation into lipids. How FakA impacts the lipid membrane composition is unknown. In this study, we used mass spectrometry to determine the membrane lipid composition and properties of S. aureus in the absence of fakA. We found the fakA mutant to have increased abundance of lipids containing longer acyl chains. Since S. aureus does not synthesize unsaturated fatty acids, we utilized oleic acid (18:1) to track exogenous fatty acid incorporation into lipids. We observed a concentration-dependent incorporation of exogenous fatty acids into the membrane that required FakA. We also tested how FakA and exogenous fatty acids impact membrane-related physiology and identified changes in membrane potential, cellular respiration, and membrane fluidity. To mimic the host environment, we characterized the lipid composition of wild-type and fakA mutant bacteria grown in mouse skin homogenate. We show that wild-type S. aureus can incorporate exogenous unsaturated fatty acids from host tissue, highlighting the importance of FakA in the presence of host skin tissue. In conclusion, FakA is important for maintaining the composition and properties of the phospholipid membrane in the presence of exogenous fatty acids, impacting overall cell physiology. IMPORTANCE Environmental fatty acids can be harvested to supplement endogenous fatty acid synthesis to produce membranes and circumvent fatty acid biosynthesis inhibitors. However, how the inability to use these fatty acids impacts lipids is unclear. Our results reveal lipid composition changes in response to fatty acid addition and when S. aureus is unable to activate fatty acids through FakA. We identify concentration-dependent utilization of oleic acid that, when combined with previous work, provides evidence that fatty acids can serve as a signal to S. aureus. Furthermore, using mouse skin homogenates as a surrogate for in vivo conditions, we showed that S. aureus can incorporate host fatty acids. This study highlights how exogenous fatty acids impact bacterial membrane composition and function. |
| Databáze: | OpenAIRE |
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