Targeting of csgD by the small regulatory RNA RprA links stationary phase, biofilm formation and cell envelope stress in Escherichia coli

verfasst von

Franziska Mika, Susan Busse, Alexandra Possling, Janine Berkholz, Natalia Tschowri, Nicole Sommerfeldt, Mihaela Pruteanu, Regine Hengge

Abstract

RprA is a small regulatory RNA known to weakly affect the translation of σ(S) (RpoS) in Escherichia coli. Here we demonstrate that csgD, which encodes a stationary phase-induced biofilm regulator, as well as ydaM, which encodes a diguanylate cyclase involved in activating csgD transcription, are novel negatively controlled RprA targets. As shown by extensive mutational analysis, direct binding of RprA to the 5'-untranslated and translational initiation regions of csgD mRNA inhibits translation and reduces csgD mRNA levels. In the case of ydaM mRNA, RprA base-pairs directly downstream of the translational start codon. In a feedforward loop, RprA can thus downregulate > 30 YdaM/CsgD-activated genes including those for adhesive curli fimbriae. However, during early stationary phase, when csgD transcription is strongly activated, the synthesis of csgD mRNA exceeds that of RprA, which allows the accumulation of CsgD protein. This situation is reversed when csgD transcription is shut off - for instance, later in stationary phase or during biofilm formation - or by conditions that further activate RprA expression via the Rcs two-component system. Thus, antagonistic regulation of csgD and RprA at the mRNA level integrates cell envelope stress signals with global gene expression during stationary phase and biofilm formation.

Organisationseinheit(en)

Institut für Mikrobiologie

Externe Organisation(en)

Freie Universität Berlin (FU Berlin)
IDT Biologika GmbH
National University of Ireland, Cork

Typ

Artikel

Journal

Molecular microbiology

Band

84

Seiten

51-65

Anzahl der Seiten

15

ISSN

0950-382X

Publikationsdatum

04.2012

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

Elektronische Version(en)

https://doi.org/10.1111/j.1365-2958.2012.08002.x (Zugang: Unbekannt)