A riboswitch-regulated antisense RNA in Listeria monocytogenes
- 22 July 2013
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 110 (32), 13132-13137
- https://doi.org/10.1073/pnas.1304795110
Abstract
Riboswitches are ligand-binding elements located in 5′ untranslated regions of messenger RNAs, which regulate expression of downstream genes. In Listeria monocytogenes, a vitamin B12-binding (B12) riboswitch was identified, not upstream of a gene but downstream, and antisense to the adjacent gene, pocR, suggesting it might regulate pocR in a nonclassical manner. In Salmonella enterica, PocR is a transcription factor that is activated by 1,2-propanediol, and subsequently activates expression of the pdu genes. The pdu genes mediate propanediol catabolism and are implicated in pathogenesis. As enzymes involved in propanediol catabolism require B12 as a cofactor, we hypothesized that the Listeria B12 riboswitch might be involved in pocR regulation. Here we demonstrate that the B12 riboswitch is transcribed as part of a noncoding antisense RNA, herein named AspocR. In the presence of B12, the riboswitch induces transcriptional termination, causing aspocR to be transcribed as a short transcript. In contrast, in the absence of B12, aspocR is transcribed as a long antisense RNA, which inhibits pocR expression. Regulation by AspocR ensures that pocR, and consequently the pdu genes, are maximally expressed only when both propanediol and B12 are present. Strikingly, AspocR can inhibit pocR expression in trans, suggesting it acts through a direct interaction with pocR mRNA. Together, this study demonstrates how pocR and the pdu genes can be regulated by B12 in bacteria and extends the classical definition of riboswitches from elements governing solely the expression of mRNAs to a wider role in controlling transcription of noncoding RNAs.This publication has 26 references indexed in Scilit:
- The excludon: a new concept in bacterial antisense RNA-mediated gene regulationNature Reviews Microbiology, 2012
- Bacterial Antisense RNAs: How Many Are There, and What Are They Doing?Annual Review of Genetics, 2010
- An antisense RNA that governs the expression kinetics of a multifunctional virulence geneMolecular Microbiology, 2010
- An overview of RNAs with regulatory functions in gram-positive bacteriaCellular and Molecular Life Sciences, 2009
- The Listeria transcriptional landscape from saprophytism to virulenceNature, 2009
- Multiple posttranscriptional regulatory mechanisms partner to control ethanolamine utilization in Enterococcus faecalisProceedings of the National Academy of Sciences of the United States of America, 2009
- Identification of new noncoding RNAs in Listeria monocytogenes and prediction of mRNA targetsNucleic Acids Research, 2007
- Comparative Genomics of the Vitamin B12 Metabolism and Regulation in ProkaryotesJournal of Biological Chemistry, 2003
- Comparison of the genome sequences ofListeria monocytogenesandListeria innocua: clues for evolution and pathogenicityFEMS Immunology & Medical Microbiology, 2003
- The Alternative Electron Acceptor Tetrathionate Supports B 12 -Dependent Anaerobic Growth of Salmonella enterica Serovar Typhimurium on Ethanolamine or 1,2-PropanediolJournal of Bacteriology, 2001