Journal
JOURNAL OF BACTERIOLOGY
Volume 196, Issue 7, Pages 1435-1447Publisher
AMER SOC MICROBIOLOGY
DOI: 10.1128/JB.01471-13
Keywords
-
Categories
Funding
- Deutsche Forschungsgemeinschaft (DFG) [Ev42/4-1, SPP 1258]
- Bundesanstalt fur Landwirtschaft und Ernahrung (BLE) [2811NA033]
- LOEWE program of the State of Hessen, Germany
- DFG [SPP 1258, grant Be2121/5-2]
- Development and Promotion of Science and Technology talents project (DPST), the Royal Thai Government
Ask authors/readers for more resources
Quorum sensing of Sinorhizobium meliloti relies on N-acyl-homoserine lactones (AHLs) as autoinducers. AHL production increases at high population density, and this depends on the AHL synthase SinI and two transcriptional regulators, SinR and ExpR. Our study demonstrates that ectopic expression of the gene rne, coding for RNase E, an endoribonuclease that is probably essential for growth, prevents the accumulation of AHLs at detectable levels. The ectopic rne expression led to a higher level of rne mRNA and a lower level of sinI mRNA independently of the presence of ExpR, the AHL receptor, and AHLs. In line with this, IPTG (isopropyl-beta-D-thiogalactopyranoside)-induced overexpression of rne resulted in a shorter half-life of sinI mRNA and a strong reduction of AHL accumulation. Moreover, using translational sinI-egfp fusions, we found that sinI expression is specifically decreased upon induced overexpression of rne, independently of the presence of the global posttranscriptional regulator Hfq. The 28-nucleotide 5' untranslated region (UTR) of sinI mRNA was sufficient for this effect. Random amplification of 5' cDNA ends (5'-RACE) analyses revealed a potential RNase E cleavage site at position +24 between the Shine-Dalgarno site and the translation start site. We postulate therefore that RNase E-dependent degradation of sinI mRNA from the 5' end is one of the steps mediating a high turnover of sinI mRNA, which allows the Sin quorum-sensing system to respond rapidly to changes in transcriptional control of AHL production.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available