Hesketh Andy, Deery Michael J, Hong Hee-Jeon
†Department of Biochemistry, University of Cambridge, Cambridge, U.K.
‡Cambridge Systems Biology Centre, University of Cambridge, Cambridge, U.K.
J Proteome Res. 2015 Jul 2;14(7):2915-28. doi: 10.1021/acs.jproteome.5b00242. Epub 2015 May 29.
Understanding how bacteria survive periods of cell wall stress is of fundamental interest and can help generate ideas for improved antibacterial treatments. In this study we use tandem mass tagging to characterize the proteomic response of vancomycin resistant Streptomyces coelicolor to the exposure to sublethal levels of the antibiotic. A common set of 804 proteins were identified in triplicate experiments. Contrasting changes in the abundance of proteins closely associated with the cytoplasmic membrane with those taking place in the cytosol identified aspects of protein spatial localization that are associated with the response to vancomycin. Enzymes for peptidoglycan precursor, mycothiol, ectoine and menaquinone biosynthesis together with a multisubunit nitrate reductase were recruited to the membrane following vancomycin treatment. Many proteins with regulatory functions (including sensor protein kinases) also exhibited significant changes in abundance exclusively in the membrane-associated protein fraction. Several enzymes predicted to be involved in extracellular peptidoglycan crossbridge formation became significantly depleted from the membrane. A comparison with data previously acquired on the changes in gene transcription following vancomycin treatment identified a common high-confidence set of changes in gene expression. Generalized changes in protein abundance indicate roles for proteolysis, the pentose phosphate pathway and a reorganization of amino acid biosynthesis in the stress response.
了解细菌如何在细胞壁应激时期存活具有根本重要性，并且有助于产生改进抗菌治疗的思路。在本研究中，我们使用串联质量标签来表征耐万古霉素的天蓝色链霉菌在暴露于亚致死水平抗生素时的蛋白质组反应。在三次重复实验中鉴定出一组共804种常见蛋白质。将与细胞质膜密切相关的蛋白质丰度变化与胞质溶胶中发生的变化进行对比，确定了与对万古霉素反应相关的蛋白质空间定位方面。万古霉素处理后，肽聚糖前体、麦角硫因、四氢嘧啶和甲萘醌生物合成的酶以及多亚基硝酸还原酶被募集到膜上。许多具有调节功能的蛋白质（包括传感蛋白激酶）在膜相关蛋白组分中也仅表现出丰度的显著变化。几种预计参与细胞外肽聚糖交联桥形成的酶从膜中显著减少。与先前获得的万古霉素处理后基因转录变化数据的比较确定了一组常见的高可信度基因表达变化。蛋白质丰度的普遍变化表明蛋白水解、磷酸戊糖途径和氨基酸生物合成的重新组织在应激反应中的作用。
