Discovery of a Novel Nitric Oxide Binding Protein and Nitric-Oxide-Responsive Signaling Pathway in Pseudomonas aeruginosa.
Discovery of a Novel Nitric Oxide Binding Protein and Nitric-Oxide-Responsive Signaling Pathway in Pseudomonas aeruginosa.
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DOI：
10.1021/acsinfecdis.7b00027
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发表时间：
2017-06-09
影响因子：
5.3
通讯作者：
Boon EM
中科院分区：
文献类型：
--
作者：
Hossain S;Boon EM
一氧化氮（NO）是一种自由基双原子气体分子，在低浓度下，在真核生物和细菌中都起着重要的信号作用。近年来，很明显，细菌对低水平的NO有反应，以调节它们的群体行为。许多细菌通过NO连接对一种被称为H-NOX（血红素-一氧化氮/氧结合结构域）的成熟NO传感器作出反应。许多其他人，如铜绿假单胞菌，在其基因组中缺乏注释的hnoX基因，但能够对低水平的NO作出反应以分散其生物膜。这表明存在以前未表征的NO传感器。在这项研究中，我们描述了一种新的一氧化氮结合蛋白（NosP; NO传感蛋白），这是更广泛的保守比H-NOX，以及一种新的NO响应途径在铜绿假单胞菌在细菌中的发现。我们证明，缺乏NosP途径的组成部分的铜绿假单胞菌突变体的生物膜失去了分散的能力，以响应NO。克隆，表达和纯化NosP后，我们发现它结合血红素和连接到NO的解离速率常数，这是可比的其他完善的NO传感蛋白。此外，我们发现NO结合的NosP能够调节参与铜绿假单胞菌生物膜调节的杂合组氨酸激酶的磷酸化活性。因此，在这里，我们提出了一种新的NO反应途径，调节铜绿假单胞菌生物膜的证据。
Nitric oxide (NO) is a radical diatomic gas molecule that, at low concentrations, plays important signaling roles in both eukaryotes and bacteria. In recent years, it has become evident that bacteria respond to low levels of NO in order to modulate their group behavior. Many bacteria respond via NO ligation to a well-established NO sensor called H-NOX (heme-nitric oxide/oxygen binding domain). Many others, such as Pseudomonas aeruginosa, lack an annotated hnoX gene in their genome yet are able to respond to low levels of NO to disperse their biofilms. This suggests the existence of a previously uncharacterized NO sensor. In this study, we describe the discovery of a novel nitric oxide binding protein (NosP; NO-sensing protein), which is much more widely conserved in bacteria than H-NOX, as well as a novel NO-responsive pathway in P. aeruginosa. We demonstrate that biofilms of a P. aeruginosa mutant lacking components of the NosP pathway lose the ability to disperse in response to NO. Upon cloning, expressing, and purifying NosP, we find it binds heme and ligates to NO with a dissociation rate constant that is comparable to that of other well-established NO-sensing proteins. Moreover, we show that NO-bound NosP is able to regulate the phosphorelay activity of a hybrid histidine kinase that is involved in biofilm regulation in P. aeruginosa. Thus, here, we present evidence of a novel NO-responsive pathway that regulates biofilm in P. aeruginosa.