Insights into transcriptional silencing and anti-silencing in Shigella flexneri: a detailed molecular analysis of the icsP virulence locus.

Autor: Weatherspoon-Griffin N; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Picker MA; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Pew KL; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Park HS; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Ginete DR; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Karney MM; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Usufzy P; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Castellanos MI; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Duhart JC; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Harrison DJ; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Socea JN; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Karabachev AD; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Hensley CT; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Howerton AJ; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Ojeda-Daulo R; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Immak JA; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA., Wing HJ; School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV 89154-4004, USA.
Jazyk: angličtina
Zdroj: Molecular microbiology [Mol Microbiol] 2018 Jun; Vol. 108 (5), pp. 505-518. Date of Electronic Publication: 2018 Mar 23.
DOI: 10.1111/mmi.13932
Abstrakt: Transcriptional silencing and anti-silencing mechanisms modulate bacterial physiology and virulence in many human pathogens. In Shigella species, many virulence plasmid genes are silenced by the histone-like nucleoid structuring protein H-NS and anti-silenced by the virulence gene regulator VirB. Despite the key role that these regulatory proteins play in Shigella virulence, their mechanisms of transcriptional control remain poorly understood. Here, we characterize the regulatory elements and their relative spacing requirements needed for the transcriptional silencing and anti-silencing of icsP, a locus that requires remotely located regulatory elements for both types of transcriptional control. Our findings highlight the flexibility of the regulatory elements' positions with respect to each other, and yet, a molecular roadblock docked between the VirB binding site and the upstream H-NS binding region abolishes transcriptional anti-silencing by VirB, providing insight into transcriptional anti-silencing. Our study also raises the need to re-evaluate the currently proposed VirB binding site. Models of transcriptional silencing and anti-silencing at this genetic locus are presented, and the implications for understanding these regulatory mechanisms in bacteria are discussed.
(© 2018 John Wiley & Sons Ltd.)
Databáze: MEDLINE
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