» Articles » PMID: 36226957

Identification of Attenuators of Transcriptional Termination: Implications for RNA Regulation in Escherichia Coli

Overview
Journal mBio
Specialty Microbiology
Date 2022 Oct 13
PMID 36226957
Authors
Affiliations
Soon will be listed here.
Abstract

The regulatory function of many bacterial small RNAs (sRNAs) requires the binding of the RNA chaperone Hfq to the 3' portion of the sRNA intrinsic terminator, and therefore sRNA signaling might be regulated by modulating its terminator. Here, using a multicopy screen developed with the terminator of sRNA SgrS, we identified an sRNA gene () and three protein-coding genes (, , and ) that attenuate SgrS termination in Escherichia coli. Analyses of CyaR and YgjH, a putative tRNA binding protein, suggested that the CyaR activity was indirect and the effect of YgjH was moderate. Overproduction of the protein attenuators CspD and Rof resulted in more frequent readthrough at terminators of SgrS and two other sRNAs, and regulation by SgrS of target mRNAs was reduced. The effect of Rof, a known inhibitor of Rho, was mimicked by bicyclomycin or by a mutant, suggesting an unexpected role for Rho in sRNA termination. CspD, a member of the cold shock protein family, bound both terminated and readthrough transcripts, stabilizing them and attenuating termination. By RNA sequencing analysis of the CspD overexpression strain, we found global effects of CspD on gene expression across some termination sites. We further demonstrated effects of endogenous CspD under slow growth conditions where is highly expressed. These findings provided evidence of changes in the efficiency of intrinsic termination, confirming this as an additional layer of the regulation of sRNA signaling. Growing evidence suggests that the modulation of intrinsic termination and readthrough of transcription is more widespread than previously appreciated. For small RNAs, proper termination plays a critical role in their regulatory function. Here, we present a multicopy screen approach to identify factors that attenuate small RNA termination and therefore abrogate signaling dependent on the small RNA. This study highlights a new aspect of regulation of small RNA signaling as well as the modulation of intrinsic termination.

Citing Articles

An internal loop region is responsible for inherent target specificity of bacterial cold-shock proteins.

Hasegawa S, Inose R, Igarashi M, Tsurumaki M, Saito M, Yanagisawa T RNA. 2024; 31(1):67-85.

PMID: 39419544 PMC: 11648934. DOI: 10.1261/rna.080163.124.


Sm-like protein Rof inhibits transcription termination factor ρ by binding site obstruction and conformational insulation.

Said N, Finazzo M, Hilal T, Wang B, Selinger T, Gjorgjevikj D Nat Commun. 2024; 15(1):3186.

PMID: 38622114 PMC: 11018626. DOI: 10.1038/s41467-024-47439-6.


Sm-like protein Rof inhibits transcription termination factor ρ by binding site obstruction and conformational insulation.

Said N, Finazzo M, Hilal T, Wang B, Selinger T, Gjorgjevikj D bioRxiv. 2023; .

PMID: 37693585 PMC: 10491184. DOI: 10.1101/2023.08.30.555460.

References
1.
Anders S, Pyl P, Huber W . HTSeq--a Python framework to work with high-throughput sequencing data. Bioinformatics. 2014; 31(2):166-9. PMC: 4287950. DOI: 10.1093/bioinformatics/btu638. View

2.
Holmqvist E, Wagner E . Impact of bacterial sRNAs in stress responses. Biochem Soc Trans. 2017; 45(6):1203-1212. PMC: 5730939. DOI: 10.1042/BST20160363. View

3.
Papenfort K, Vanderpool C . Target activation by regulatory RNAs in bacteria. FEMS Microbiol Rev. 2015; 39(3):362-78. PMC: 4542691. DOI: 10.1093/femsre/fuv016. View

4.
Yamanaka K, Fang L, Inouye M . The CspA family in Escherichia coli: multiple gene duplication for stress adaptation. Mol Microbiol. 1998; 27(2):247-55. DOI: 10.1046/j.1365-2958.1998.00683.x. View

5.
Melamed S, Adams P, Zhang A, Zhang H, Storz G . RNA-RNA Interactomes of ProQ and Hfq Reveal Overlapping and Competing Roles. Mol Cell. 2019; 77(2):411-425.e7. PMC: 6980735. DOI: 10.1016/j.molcel.2019.10.022. View