CsrA-Controlled Proteins Reveal New Dimensions of Acinetobacter baumannii Desiccation Tolerance.
CsrA-Controlled Proteins Reveal New Dimensions of Acinetobacter baumannii Desiccation Tolerance.
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CsrA 控制的蛋白质揭示了鲍曼不动杆菌干燥耐受性的新维度。
DOI：
10.1128/jb.00479-21
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发表时间：
2022
影响因子：
3.2
通讯作者：
Harwood,CarolineS
中科院分区：
文献类型：
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作者：
Oda,Yasuhiro;Shapiro,MadelynM;Lewis,NathanM;Zhong,Xuefei;Huse,HollyK;Zhong,Weizhi;Bruce,JamesE;Manoil,Colin;Harwood,CarolineS
医院环境是机会性病原体鲍曼不动杆菌的绝佳储存库，部分原因是它具有极强的耐干燥能力。我们发现，相对于其他鲍曼不动杆菌菌株，强毒菌株 AB5075 在 2% 相对湿度 (RH) 下具有显着的抗干燥性，这表明它是研究该性状功能基础的良好模型。与其他鲍曼不动杆菌菌株在 40% RH 下的结果一致，我们发现全局转录后调节因子 CsrA 对于 AB5075 在 2% RH 下的干燥耐受性至关重要。蛋白质组学实验鉴定出野生型和csr突变细胞中存在差异的蛋白质。随后对编码其中一些蛋白质的基因突变体的分析揭示了野生型水平的干燥耐受性所需的六个基因。其中包括过氧化氢酶基因、通用应激蛋白、假设蛋白和生物膜相关蛋白。两个功能未知的基因具有非常强的干燥表型，这两个基因之一预测了一种与 DNA 结合的本质无序蛋白 (IDP)。本质无序蛋白质在真核生物中广泛存在，但在原核生物中较少见。我们的结果表明，细菌的干燥耐受性存在新的机制，并确定了其中涉及的几个关键功能。 重要性 鲍曼不动杆菌存在于陆地环境中，但可导致病情严重的患者发生院内感染。导致鲍曼不动杆菌在医院环境中流行的一个因素是它本质上对干燥条件有抵抗力。在这里，我们建立了强毒菌株鲍曼不动杆菌 AB5075 作为研究极低相对湿度下干燥耐受性的模型。我们的结果表明，这一性状取决于两种功能未知的蛋白质，其中一种预计是一种本质上无序的蛋白质。这类蛋白质对于缓步类小动物在干燥条件下生存至关重要。我们的结果表明，鲍曼不动杆菌可能具有以前在细菌中未曾见过的新颖的干燥策略。
Hospital environments are excellent reservoirs for the opportunistic pathogen Acinetobacter baumannii in part because it is exceptionally tolerant to desiccation. We found that relative to other A. baumannii strains, the virulent strain AB5075 was strikingly desiccation resistant at 2% relative humidity (RH), suggesting that it is a good model for studies of the functional basis of this trait. Consistent with results from other A. baumannii strains at 40% RH, we found the global posttranscriptional regulator CsrA to be critically important for desiccation tolerance of AB5075 at 2% RH. Proteomics experiments identified proteins that were differentially present in wild-type andcsrAmutant cells. Subsequent analysis of mutants in genes encoding some of these proteins revealed six genes that were required for wild-type levels of desiccation tolerance. These include genes for catalase, a universal stress protein, a hypothetical protein, and a biofilm-associated protein. Two genes of unknown function had very strong desiccation phenotypes, with one of the two genes predicting an intrinsically disordered protein (IDP) that binds to DNA. Intrinsically disordered proteins are widespread in eukaryotes but less so in prokaryotes. Our results suggest there are new mechanisms underlying desiccation tolerance in bacteria and identify several key functions involved.IMPORTANCEAcinetobacter baumannii is found in terrestrial environments but can cause nosocomial infections in very sick patients. A factor that contributes to the prevalence of A. baumannii in hospital settings is that it is intrinsically resistant to dry conditions. Here, we established the virulent strain A. baumannii AB5075 as a model for studies of desiccation tolerance at very low relative humidity. Our results show that this trait depends on two proteins of unknown function, one of which is predicted to be an intrinsically disordered protein. This category of protein is critical for the small animals named tardigrades to survive desiccation. Our results suggest that A. baumannii may have novel strategies to survive desiccation that have not previously been seen in bacteria.