PadR-type repressors controlling production of a non-canonical FtsW/RodA homologue and other trans-membrane proteins
PadR-type repressors controlling production of a non-canonical FtsW/RodA homologue and other trans-membrane proteins
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DOI：
10.1038/s41598-019-46347-w
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发表时间：
2019-07-11
影响因子：
4.6
通讯作者：
Halbedel, Sven
中科院分区：
文献类型：
--
作者：
Hauf, Samuel;Moller, Lars;Halbedel, Sven
革兰氏阳性细菌单核细胞增生李斯特菌在环境中普遍存在，并在摄入后感染人类。它编码四个PadR样阻遏物，其中LftR先前已被表征，并显示出响应于其他环境细菌产生的抗生素aurantiomycin控制基因表达。为了更好地了解L.在单核细胞增多症中，我们用其他三种阻遏物LadR、LstR和Lmo 0599的突变体进行RNA测序。我们发现，LadR主要负责调节mdrL基因，编码外排泵，而LstR和Lmo 0599主要调节自己的操纵子。lstR操纵子含有lmo 0421基因，编码RodA/FtsW蛋白家族的同源物。然而，正如我们在这里证明的那样，这种蛋白质不具有这种功能。lmo 0599操纵子含有两个额外的基因，编码假定的跨膜蛋白lmo 0600和lmo 0601。lmo 0599突变体的一个显著表型是其在冷藏温度下的生长受损。根据这些和其他结果，我们建议Lmo 0599应重新命名，并建议LltR（连续低温调节器）作为其新名称。基于PadR靶基因的性质，我们假设这些阻遏物共同响应作用于细胞包膜的化合物。
The Gram-positive bacterium Listeria monocytogenes occurs ubiquitously in the environment and infects humans upon ingestion. It encodes four PadR-like repressors, out of which LftR has been characterized previously and was shown to control gene expression in response to the antibiotic aurantimycin produced by other environmental bacteria. To better understand the PadR regulons of L. monocytogenes, we performed RNA-sequencing with mutants of the other three repressors LadR, LstR and Lmo0599. We show that LadR is primarily responsible for the regulation of the mdrL gene, encoding an efflux pump, while LstR and Lmo0599 mainly regulate their own operons. The lstR operon contains the lmo0421 gene, encoding a homolog of the RodA/FtsW protein family. However, this protein does not possess such functionality, as we demonstrate here. The lmo0599 operon contains two additional genes coding for the hypothetical trans-membrane proteins lmo0600 and lmo0601. A striking phenotype of the lmo0599 mutant is its impaired growth at refrigeration temperature. In light of these and other results we suggest that Lmo0599 should be renamed and propose LltR (listerial low temperature regulator) as its new designation. Based on the nature of the PadR target genes we assume that these repressors collectively respond to compounds acting on the cellular envelope.