Institute for Microbiology, Department of Microbial Physiology, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany.
Proteomics. 2010 Apr;10(8):1685-93. doi: 10.1002/pmic.200900772.
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.
细菌细胞质膜的动态脂质组成对细菌的重要适应能力和对膜损伤剂、温度或渗透压应激的敏感性有深远的影响。然而，脂质模式的变化如何影响膜蛋白的丰度和表达，在很大程度上仍然未知。使用最近开发的无胶质蛋白质组学技术，我们研究了重要的人体病原体金黄色葡萄球菌在存在或不存在阳性磷脂赖氨酸磷酸甘油（Lys-PG）的情况下的膜蛋白质组。我们几乎能够检测到所有理论上的整合膜蛋白的一半，并能够可靠地定量超过 35%的蛋白质。值得注意的是，赖氨酸磷酸甘油合成酶 MprF 的缺失并没有导致大量的改变，而是非常明显地只调节了 1.5%或 3.5%的定量蛋白质的上调或下调。赖氨酸磷酸甘油缺乏对脂质生物合成酶的丰度没有重大影响，但显著影响了细胞包膜应激感应调节蛋白，如 SaeS 和 MsrR，以及 SaeS 调节蛋白 Sbi、Efb 和 SaeP 的含量。这些数据表明，膜感应蛋白与磷脂之间存在非常关键的相互作用，并证明了膜蛋白质组学在描述细菌生理学和致病性方面的强大功能。
