Quorum regulatory small RNAs repress type VI secretion in Vibrio cholerae.

TitleQuorum regulatory small RNAs repress type VI secretion in Vibrio cholerae.
Publication TypeJournal Article
Year of Publication2014
AuthorsShao, Y, Bassler, BL
JournalMol Microbiol
Volume92
Issue5
Pagination921-30
Date Published2014 Jun
ISSN1365-2958
KeywordsBacterial Proteins, Gene Expression Regulation, Bacterial, Quorum Sensing, RNA, Bacterial, Vibrio cholerae
Abstract

<p>Type VI secretion is critical for Vibrio cholerae to successfully combat phagocytic eukaryotes and to survive in the presence of competing bacterial species. V. cholerae type VI secretion system genes are encoded in one large and two small clusters. In V. cholerae, type VI secretion is controlled by quorum sensing, the cell-cell communication process that enables bacteria to orchestrate group behaviours. The quorum-sensing response regulator LuxO represses type VI secretion genes at low cell density and the quorum-sensing regulator HapR activates type VI secretion genes at high cell density. We demonstrate that the quorum regulatory small RNAs (Qrr sRNAs) that function between LuxO and HapR in the quorum-sensing cascade are required for these regulatory effects. The Qrr sRNAs control type VI secretion via two mechanisms: they repress expression of the large type VI secretion system cluster through base pairing and they repress HapR, the activator of the two small type VI secretion clusters. This regulatory arrangement ensures that the large cluster encoding many components of the secretory machine is expressed prior to the two small clusters that encode the secreted effectors. Qrr sRNA-dependent regulation of the type VI secretion system is conserved in pandemic and non-pandemic V. cholerae strains.</p>

DOI10.1111/mmi.12599
Alternate JournalMol. Microbiol.
PubMed ID24698180
PubMed Central IDPMC4038675
Grant List5R01GM065859 / GM / NIGMS NIH HHS / United States
R01 GM065859 / GM / NIGMS NIH HHS / United States
T32 GM007388 / GM / NIGMS NIH HHS / United States
/ / Howard Hughes Medical Institute / United States