Widespread targeting of nascent transcripts by RsmA in Pseudomonas aeruginosa
Widespread targeting of nascent transcripts by RsmA in Pseudomonas aeruginosa
复制标题
DOI：
10.1073/pnas.1917587117
复制
发表时间：
2020-05-12
影响因子：
11.1
通讯作者：
Dove, Simon L.
中科院分区：
文献类型：
--
作者：
Gebhardt, Michael J.;Kambara, Tracy K.;Dove, Simon L.
在条件致病菌铜绿假单胞菌中，RsmA是一种RNA结合蛋白，在控制毒力、细菌间相互作用和生物膜形成中起关键作用。尽管RsmA被认为通过结合全长转录本来发挥其调节作用，但RsmA结合新生转录本的程度尚未得到解决。此外，这一关键的转录后调节因子的直接目标是在很大程度上是未知的。使用染色质免疫沉淀结合高通量DNA测序，在RNA聚合酶抑制剂利福平存在和不存在的情况下生长的细胞，我们确定了数百个新生的转录本，RsmA协会与铜绿假单胞菌。我们还发现，RNA分子伴侣Hfq的目标是那些新生的转录子，RsmA协会的一个子集，这两个RNA结合蛋白可以发挥调节作用的共同目标。我们的研究结果表明，RsmA与许多转录本，因为他们正在合成铜绿假单胞菌，确定RsmA靶向的转录本，并表明，RsmA和Hfq可能在某些转录本上的组合方式。转录后调节因子与新生转录物的结合在细菌中可能是常见的，其中不同的调节因子可以单独或协同发挥作用，以在转录物从RNA聚合酶中出现后立即控制转录物的翻译。
In the opportunistic pathogen Pseudomonas aeruginosa, RsmA is an RNA-binding protein that plays critical roles in the control of virulence, interbacterial interactions, and biofilm formation. Although RsmA is thought to exert its regulatory effects by binding full-length transcripts, the extent to which RsmA binds nascent transcripts has not been addressed. Moreover, which transcripts are direct targets of this key posttranscriptional regulator is largely unknown. Using chromatin immunoprecipitation coupled with high-throughput DNA sequencing, with cells grown in the presence and absence of the RNA polymerase inhibitor rifampicin, we identify hundreds of nascent transcripts that RsmA associates with in P. aeruginosa. We also find that the RNA chaperone Hfq targets a subset of those nascent transcripts that RsmA associates with and that the two RNA-binding proteins can exert regulatory effects on common targets. Our findings establish that RsmA associates with many transcripts as they are being synthesized in P. aeruginosa, identify the transcripts targeted by RsmA, and suggest that RsmA and Hfq may act in a combinatorial fashion on certain transcripts. The binding of posttranscriptional regulators to nascent transcripts may be commonplace in bacteria where distinct regulators can function alone or in concert to achieve control over the translation of transcripts as soon as they emerge from RNA polymerase.