Open AccessVirF-Independent Regulation of Shigella virB Transcription is Mediated by the Small RNA RyhB
Author(s) -
William H. Broach,
Nicholas Egan,
Helen J. Wing,
Shelley M. Payne,
Erin R. Murphy
Publication year - 2012
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0038592
Subject(s) - biology , transcription (linguistics) , virulence , transcription factor , promoter , regulator , gene , activator (genetics) , transcriptional regulation , genetics , regulation of gene expression , gene expression , philosophy , linguistics
Infection of the human host by Shigella species requires the coordinated production of specific Shigella virulence factors, a process mediated largely by the VirF/VirB regulatory cascade. VirF promotes the transcription of virB , a gene encoding the transcriptional activator of several virulence-associated genes. This study reveals that transcription of virB is also regulated by the small RNA RyhB, and importantly, that this regulation is not achieved indirectly via modulation of VirF activity. These data are the first to demonstrate that the regulation of virB transcription can be uncoupled from the master regulator VirF. It is also established that efficient RyhB-dependent regulation of transcription is facilitated by specific nucleic acid sequences within virB . This study not only reveals RyhB-dependent regulation of virB transcription as a novel point of control in the central regulatory circuit modulating Shigella virulence, but also highlights the versatility of RyhB in controlling bacterial gene expression.