Galea Diana, Herzberg Martin, Dobritzsch Dirk, Fuszard Matt, Nies Dietrich H
Institute for Biology/Microbiology, Martin-Luther-University Halle-Wittenberg, 06099 Halle (Saale), Germany.
Department of Analytical Chemistry, Helmholtz Centre for Environmental Research-UFZ, Leipzig 04318, Germany.
Metallomics. 2024 Dec 2;16(12). doi: 10.1093/mtomcs/mfae058.
Cupriavidus metallidurans CH34 is a metal-resistant bacterium. Its metal homeostasis is based on a flow equilibrium of metal ion uptake and efflux reactions, which adapts to changing metal concentrations within an hour. At high metal concentrations, upregulation of the genes for metal efflux systems occurs within minutes. Here, we investigate the changes in the bacterial proteome accompanying these genetic and physiological events after 1.5 cell duplications, which took 3 h. To that end, C. metallidurans CH34 and its plasmid-free derivative, AE104, either were challenged with a toxic metal mix or were cultivated under metal-starvation conditions, followed by bottom-up proteomics. When metal-shocked or -starved cells were compared with their respective controls, 3540 proteins changed in abundance, with 76% appearing in one, but not the other, condition; the remaining 24% were up- or downregulated. Metal-shocked C. metallidurans strains had adjusted their proteomes to combat metal stress. The most prominent polypeptides were the products of the plasmid-encoded metal-resistance determinants in strain CH34, particularly the CzcCBA transenvelope efflux system. Moreover, the influence of antisense transcripts on the proteome was also revealed. In one specific example, the impact of an asRNA on the abundance of gene products could be demonstrated and this yielded new insights into the function of the transmembrane efflux complex ZniCBA under conditions of metal starvation.
金属抗性细菌嗜金属贪铜菌CH34是一种抗金属细菌。其金属稳态基于金属离子摄取和外排反应的流量平衡，这种平衡能在一小时内适应不断变化的金属浓度。在高金属浓度下，金属外排系统基因在数分钟内就会上调。在此，我们研究了在1.5次细胞复制（耗时3小时）后，伴随这些遗传和生理事件的细菌蛋白质组的变化。为此，嗜金属贪铜菌CH34及其无质粒衍生物AE104，要么用有毒金属混合物进行挑战，要么在金属饥饿条件下培养，随后进行自下而上的蛋白质组学分析。当将金属冲击或饥饿处理的细胞与其各自的对照进行比较时，有3540种蛋白质的丰度发生了变化，其中76%只出现在一种处理条件下，而不出现在另一种条件下；其余24%的蛋白质上调或下调。受到金属冲击的嗜金属贪铜菌菌株已调整其蛋白质组以应对金属胁迫。最突出的多肽是CH34菌株中质粒编码的金属抗性决定因子的产物，特别是CzcCBA跨膜外排系统。此外，还揭示了反义转录本对蛋白质组的影响。在一个具体例子中，可以证明一种反义RNA对基因产物丰度的影响，这为金属饥饿条件下跨膜外排复合物ZniCBA的功能提供了新的见解。
