Hierarchy in Hfq Chaperon Occupancy of Small RNA Targets Plays a Major Role in Their Regulation
Hierarchy in Hfq Chaperon Occupancy of Small RNA Targets Plays a Major Role in Their Regulation
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DOI：
10.1016/j.celrep.2020.02.016
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发表时间：
2020-03-03
期刊：
影响因子：
8.8
通讯作者：
Margalit, Hanah
中科院分区：
文献类型：
--
作者：
Faigenbaum-Romm, Raya;Reich, Avichai;Margalit, Hanah
细菌小RNA（sRNA）是基因表达的转录后调节因子，其与靶mRNA上的互补序列碱基配对，通常与伴侣分子Hfq相关联。在这里，使用实验确定的sRNA靶对，沿着基因表达测量，我们评估sRNA调控的基本原则。我们表明，sRNA序列决定的目标库，作为点突变的sRNA转移相应的目标集。我们区分两个子集的目标：目标显示其sRNA调节剂的过表达下的表达水平的变化和未受影响的目标，更零星地与sRNA相互作用。靶点之间的这些差异与它们的Hfq占有率相关，而不是与sRNA-靶点碱基配对潜力相关。我们的研究结果表明，目标之间的竞争在Hfq结合的监管结果中起着重要作用，可能授予目标具有较高的Hfq结合效率的优势，在竞争中结合的sRNA。
Bacterial small RNAs (sRNAs) are posttranscriptional regulators of gene expression that base pair with complementary sequences on target mRNAs, often in association with the chaperone Hfq. Here, using experimentally identified sRNA-target pairs, along with gene expression measurements, we assess basic principles of regulation by sRNAs. We show that the sRNA sequence dictates the target repertoire, as point mutations in the sRNA shift the target set correspondingly. We distinguish two subsets of targets: targets showing changes in expression levels under overexpression of their sRNA regulator and unaffected targets that interact more sporadically with the sRNA. These differences among targets are associated with their Hfq occupancy, rather than with the sRNA-target base-pairing potential. Our results suggest that competition among targets over Hfq binding plays a major role in the regulatory outcome, possibly awarding targets with higher Hfq binding efficiency an advantage in the competition over binding to the sRNA.