RpoS and quorum sensing control expression and polar localization of Vibrio cholerae chemotaxis cluster III proteins in vitro and in vivo. Issue 4 (6th June 2015)

• Record Type: Journal Article
• Authors: Ringgaard, Simon; Hubbard, Troy; Mandlik, Anjali; Davis, Brigid M.; Waldor, Matthew K.
• Is Part Of: Molecular microbiology. Volume 97:Issue 4(2015)
• Page Start: 660
• Page End: 675
• Publication Date: 2015-06-06
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.13053
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>The diarrheal pathogen <italic>V</italic><italic>ibrio cholerae</italic> contains three gene clusters that encode chemotaxis‐related proteins, but only cluster II appears to be required for chemotaxis. Here, we present the first characterization of <italic>V</italic><italic>. cholerae</italic>'s 'cluster III' chemotaxis system. We found that cluster III proteins assemble into foci at bacterial poles, like those formed by cluster II proteins, but the two systems assemble independently and do not colocalize. Cluster III proteins are expressed <italic>in vitro</italic> during stationary phase and in conjunction with growth arrest linked to carbon starvation. This expression, as well as expression <italic>in vivo</italic> in suckling rabbits, is dependent upon RpoS. <italic>V</italic><italic>. cholerae</italic>'s CAI‐1 quorum sensing (QS) system is also required for cluster III expression in stationary phase and modulates its expression <italic>in vivo</italic>, but is not required for cluster III expression in response to carbon starvation. Surprisingly, even though the CAI‐1 and AI‐2 QS systems are thought to feed into the same signaling pathway, the AI‐2 system inhibited cluster III gene expression, revealing that the outputs of the two QS systems are not always the same. The distinctions between genetic determinants of cluster III expression <italic>in vitro</italic> and <italic>in vivo</italic> highlight the distinctive nature of the <italic>in vivo</italic> environment.</p> </abstract>