GlmY and GlmZ: A regulatory cascade composed of two small RNAs

• Antragsteller: Professor Dr. Boris Görke
• Fachliche Zuordnung: Stoffwechselphysiologie, Biochemie und Genetik der Mikroorganismen
• Förderung: Förderung von 2010 bis 2014
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 169497720

In Escherichia coli, synthesis of the central metabolic enzyme glucosamine-6-phosphate (GlcN6P) synthase GlmS is feedback-regulated by a regulatory cascade composed of two homologous sRNAs. GlmS catalyzes the formation of GlcN6P, which is required for biosynthesis of the cell wall. A decreasing GlcN6P concentration induces accumulation of sRNA GlmY, which in turn counteracts processing of the second sRNA, GlmZ. Exclusively full-length GlmZ base-pairs with the glmS transcript and stimulates GlmS synthesis. Expression of glmY is controlled by the two-component system GlrR/GlrK, but sensing of the GlcN6P signal takes place post glmY transcription. In the proposed project three questions shall be addressed: First, the GlcN6P sensing mechanism shall be identified. We speculate that this step might involve binding of GlmY by protein YhbJ. We recently identified YhbJ to be required for GlmZ processing. Second, the mechanism of signal transduction between GlmY and GlmZ shall be clarified. Our data are consistent with a model, in which binding of GlmY to YhbJ triggers processing of GlmZ, either by affecting the interaction of YhbJ with the GlmZ processing enzyme or by controlling expression of a factor that in turn controls activity of this RNase. For the latter, the RNase E inhibitory protein RraB is a good candidate, because its synthesis is regulated by GlcN6P. Finally, the signal sensed by GlrK/GlrR shall be identified. This will reveal functions that GlmY has in addition to the control of GlmZ and glmS.

• DFG-Verfahren: Schwerpunktprogramme
• Teilprojekt zu: SPP 1258: Sensory and regulatory RNAs in Prokaryotes