Changing the phospholipid composition of Staphylococcus aureus causes distinct changes in membrane proteome and membrane-sensory regulators.
The dynamic lipid composition of bacterial cytoplasmic membranes has a profound impact on vital bacterial fitness and susceptibility to membrane-damaging agents, temperature, or osmotic stress. However, it has remained largely unknown how changes in lipid patterns affect the abundance and expression of membrane proteins. Using recently developed gel-free proteomics technology, we explored the membrane proteome of the important human pathogen Staphylococcus aureus in the presence or absence of the cationic phospholipid lysyl-phosphatidylglycerol (Lys-PG). We were able to detect almost half of all theoretical integral membrane proteins and could reliably quantify more than 35% of them. It is worth noting that the deletion of the Lys-PG synthase MprF did not lead to a massive alteration but a very distinct up- or down-regulation of only 1.5 or 3.5% of the quantified proteins. Lys-PG deficiency had no major impact on the abundance of lipid-biosynthetic enzymes but significantly affected the amounts of the cell envelope stress-sensing regulatory proteins such as SaeS and MsrR, and of the SaeS-regulated proteins Sbi, Efb, and SaeP. These data indicate very critical interactions of membrane-sensory proteins with phospholipids and they demonstrate the power of membrane proteomics for the characterization of bacterial physiology and pathogenicity.
Sievers
Susanne
S
Institute for Microbiology, Department of Microbial Physiology, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany. susanne.wolff@uni-greifswald.de
Ernst
Christoph M
CM
Geiger
Tobias
T
Hecker
Michael
M
Wolz
Christiane
C
Becher
Dörte
D
Peschel
Andreas
A
D001426:Bacterial Proteins / Q000032:analysis*; D002462:Cell Membrane / Q000737:chemistry*; D008565:Membrane Proteins / Q000032:analysis*; D010743:Phospholipids / Q000032:analysis*; D020543:Proteome / Q000032:analysis*; D013211:Staphylococcus aureus / Q000737:chemistry*
D001426:Bacterial Proteins; D008565:Membrane Proteins; D010743:Phospholipids; D020543:Proteome