An RNA-dependent mechanism for transient expression of bacterial translocation filaments.
An RNA-dependent mechanism for transient expression of bacterial translocation filaments.
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DOI：
10.1093/nar/gky096
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发表时间：
2018-04-20
影响因子：
14.9
通讯作者：
Gally DL
中科院分区：
文献类型：
--
作者：
Wang D;McAteer SP;Wawszczyk AB;Russell CD;Tahoun A;Elmi A;Cockroft SL;Tollervey D;Granneman S;Tree JJ;Gally DL
原核RNA伴侣Hfq介导sRNA-mRNA相互作用，并在一系列大肠杆菌致病型产生的III型分泌（T3 S）系统的转录后调节中起重要作用。紫外线交联被用来映射Hfq结合的条件下，促进T3 S和多种相互作用被确定内的多顺反子转录产生的基因座的肠上皮细胞消失（LEE）编码的T3 S系统。大部分Hfq结合在LEE 5和LEE 4操纵子内，后者编码由RNA结合蛋白CsrA正调控的转位子装置（SepL-EspADB）。使用鉴定的Hfq结合位点和一系列sRNA缺失，sRNA Spot 42显示直接抑制LEE 4在sepL 5′ UTR的翻译。在计算机和体内分析的sepL mRNA二级结构结合表达研究的截断表明，未结合的sepL mRNA是无活性的。基于定点突变体的表达研究，提出了一种OFF-ON-OFF切换模型，该模型导致SepL和EspA细丝组装的瞬时翻译。在该模型下，新生mRNA在被CsrA激活之前被抑制关闭，然后被Hfq和Spot 42抑制。
The prokaryotic RNA chaperone Hfq mediates sRNA–mRNA interactions and plays a significant role in post-transcriptional regulation of the type III secretion (T3S) system produced by a range of Escherichia coli pathotypes. UV-crosslinking was used to map Hfq-binding under conditions that promote T3S and multiple interactions were identified within polycistronic transcripts produced from the locus of enterocyte effacement (LEE) that encodes the T3S system. The majority of Hfq binding was within the LEE5 and LEE4 operons, the latter encoding the translocon apparatus (SepL-EspADB) that is positively regulated by the RNA binding protein, CsrA. Using the identified Hfq-binding sites and a series of sRNA deletions, the sRNA Spot42 was shown to directly repress translation of LEE4 at the sepL 5′ UTR. In silico and in vivo analyses of the sepL mRNA secondary structure combined with expression studies of truncates indicated that the unbound sepL mRNA is translationally inactive. Based on expression studies with site-directed mutants, an OFF-ON-OFF toggle model is proposed that results in transient translation of SepL and EspA filament assembly. Under this model, the nascent mRNA is translationally off, before being activated by CsrA, and then repressed by Hfq and Spot42.
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影响因子：
3.6
作者：
BLOMFIELD, IC;VAUGHN, V;EISENSTEIN, BI
通讯作者：
EISENSTEIN, BI
Lee4操纵子在Enterohaemorrhagic Escherichia Coli中的转录后处理。
影响因子：
3.6
作者：
Lodato PB;Kaper JB
通讯作者：
Kaper JB
影响因子：
6.4
作者：
Emmerson, James R.;Gally, David L.;Roe, Andrew J.
通讯作者：
Roe, Andrew J.
影响因子：
3.2
作者：
Kresse, AU;Beltrametti, F;Guzmán, CA
通讯作者：
Guzmán, CA
影响因子：
5.7
作者：
Bhatt S;Egan M;Jenkins V;Muche S;El-Fenej J
通讯作者：
El-Fenej J