Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada Le Grazie 15, 37134 Verona, Italy.
J Proteome Res. 2012 Aug 3;11(8):4169-79. doi: 10.1021/pr300281f. Epub 2012 Jul 24.
Pseudomonas putida is a saprophytic bacterium with remarkable environmental adaptability and the capacity to tolerate high concentrations of heavy metals. The strain P. putida-Cd001 was isolated from soil contaminated with Cd, Zn and Pb. Membrane-associated and cytosolic proteomes were analyzed to identify proteins whose expression was modulated in response to 250 μM CdSO4. We identified 44 protein spots in the membrane and 21 in the cytosolic fraction differentially expressed in Cd-treated samples compared to untreated controls. Outer membrane porins from the OprD and OprI families were less abundant in bacteria exposed to Cd, whereas those from the OprF and OprL, OprH and OprB families were more abundant, reflecting the increased need to acquire energy sources, the need to maintain membrane integrity and the process of adaptation. Components of the efflux system, such as the CzcB subunit of the CBA system, were also induced by Cd. Analysis of the cytosolic proteome revealed that proteins involved in protein synthesis, degradation and folding were induced along with enzymes that combat oxidative stress, showing that the entire bacterial proteome is modulated by heavy metal exposure. This analysis provides new insights into the adaptation mechanisms used by P. putida-Cd001 to survive in Cd-polluted environments.
铜绿假单胞菌是一种具有显著环境适应性和耐受高浓度重金属能力的腐生菌。菌株 P. putida-Cd001 是从含有 Cd、Zn 和 Pb 的污染土壤中分离出来的。分析了膜相关和细胞质蛋白组，以鉴定对 250 μM CdSO4 有响应的表达被调节的蛋白质。与未处理对照相比，在 Cd 处理样品中鉴定到膜上的 44 个蛋白斑点和细胞质部分的 21 个蛋白斑点差异表达。暴露于 Cd 中的细菌中，OprD 和 OprI 家族的外膜孔蛋白丰度较低，而 OprF 和 OprL、OprH 和 OprB 家族的孔蛋白丰度较高，这反映了获得能源的需求增加、维持膜完整性的需求以及适应过程。CzcB 亚基等外排系统的组成部分也被 Cd 诱导。细胞质蛋白组分析表明，与对抗氧化应激的酶一起，参与蛋白质合成、降解和折叠的蛋白质被诱导，表明整个细菌蛋白质组受到重金属暴露的调节。该分析为 P. putida-Cd001 用于在 Cd 污染环境中生存的适应机制提供了新的见解。
