The Vibrio parahaemolyticus small RNA ryhB promotes production of the siderophore vibrioferrin by stabilizing the polycistronic mRNA.
The Vibrio parahaemolyticus small RNA ryhB promotes production of the siderophore vibrioferrin by stabilizing the polycistronic mRNA.
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副溶血弧菌小 RNA ryhB 通过稳定多顺反子 mRNA 来促进铁载体弧菌铁蛋白的产生。
DOI：
10.1128/jb.00162-13
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
S.
中科院分区：
文献类型：
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作者：
Tanabe;T.;Funahashi;T.;Nakao;H.;Maki;J.;Yamamoto;S.
副溶血性弧菌中高亲和力铁的获得是由同源铁载体弧菌铁蛋白介导的。我们以前曾报道，弧菌铁蛋白生物合成操纵子（pvsOp）在转录水平上受铁反应阻遏物Fur（T.田边、T. Funahashi，H. Nakao，S. Miyoshi，S. Shinoda和S. Yamamoto，J. Bacteriol. 185：6938-6949，2003）。在这项研究中，我们确定了毛皮调节的小RNA RyhB和RNA伴侣Hfq蛋白作为额外的调节蛋白的弧菌铁蛋白的生物合成。我们发现在两个RyhBandhfq缺失突变体中，弧菌铁蛋白的产生都受到了极大的损害，并且TargetRNA搜索（http：//snowwhite.wellesley.edu/targetRNA/index2.html）显示pvsOp mRNA的5′-非翻译区（pvsOp 5′-UTR）包含形成RyhB-pvsOp 5′-UTR双链体所需的潜在碱基配对区域。电泳迁移率变动分析表明，RyhB可与pvsOp的5′-UTR结合。利福平追踪实验表明，在ryhB和Hfq突变株中pvsOp mRNA的半衰期比亲本株短约3倍，表明RyhB和Hfq都参与pvsOp mRNA的稳定。Chrome azurol S分析、电泳迁移率变动分析和利福平追踪实验表明，RyhB与pvsOp 5′-UTR之间的碱基配对增加了pvsOp mRNA的稳定性，从而促进了Vibrioferrin的产生。这是前所未有的，RyhB赋予增加的稳定性的多顺反子mRNA参与铁载体生物合成作为直接目标。
High-affinity iron acquisition in Vibrio parahaemolyticus is mediated by the cognate siderophore vibrioferrin. We have previously reported that the vibrioferrin biosynthesis operon (pvsOp) is regulated at the transcriptional level by the iron-responsive repressor Fur (T. Tanabe, T. Funahashi, H. Nakao, S. Miyoshi, S. Shinoda, and S. Yamamoto, J. Bacteriol. 185:6938–6949, 2003). In this study, we identified the Fur-regulated small RNA RyhB and the RNA chaperone Hfq protein as additional regulatory proteins of vibrioferrin biosynthesis. We found that vibrioferrin production was greatly impaired in both theryhBandhfqdeletion mutants, and a TargetRNA search (http://snowwhite.wellesley.edu/targetRNA/index2.html) revealed that the 5′-untranslated region ofpvsOp mRNA (pvsOp 5′-UTR) contains a potential base-pairing region required for the formation of the RyhB-pvsOp 5′-UTR duplex. An electrophoresis mobility shift assay indicated that RyhB can directly bind to thepvsOp 5′-UTR with the aid of Hfq. Rifampin chase experiments indicated that the half-life ofpvsOp mRNA in theryhBandhfqmutants was approximately 3-fold shorter than that in the parental strain, suggesting that both RyhB and Hfq are engaged in the stabilization ofpvsOp mRNA. Chrome azurol S assays followed by electrophoresis mobility shift assays and rifampin chase experiments carried out for mutant strains indicated that base pairing between RyhB and thepvsOp 5′-UTR results in an increase in the stability ofpvsOp mRNA, thereby leading to the promotion of vibrioferrin production. It is unprecedented that RyhB confers increased stability on a polycistronic mRNA involved in siderophore biosynthesis as a direct target.