Base Pairing Interaction between 5′- and 3′-UTRs Controls icaR mRNA Translation in Staphylococcus aureus

作者：Igor Ruiz de los Mozos, Marta Vergara-Irigaray, Víctor Segura, Maite Villanueva, Nerea Bitarte, Margarida Saramago, Susana Domingues, Cecília M. Arraiano, Pierre Fechter, Pascale Romby, Jaione Valle, Cristina Solano, Íñigo Lasa, Alejandro Toledo‐Arana · 发表于：PLoS Genetics · 年份：2013 · DOI：10.1371/journal.pgen.1004001 · 被引用次数：108 · 研究领域：RNA and protein synthesis mechanisms、Bacterial Genetics and Biotechnology、Antimicrobial Resistance in Staphylococcus

The presence of regulatory sequences in the 3' untranslated region (3'-UTR) of eukaryotic mRNAs controlling RNA stability and translation efficiency is widely recognized. In contrast, the relevance of 3'-UTRs in bacterial mRNA functionality has been disregarded. Here, we report evidences showing that around one-third of the mapped mRNAs of the major human pathogen Staphylococcus aureus carry 3'-UTRs longer than 100-nt and thus, potential regulatory functions. We selected the long 3'-UTR of icaR, which codes for the repressor of the main exopolysaccharidic compound of the S. aureus biofilm matrix, to evaluate the role that 3'-UTRs may play in controlling mRNA expression. We showed that base pairing between the 3'-UTR and the Shine-Dalgarno (SD) region of icaR mRNA interferes with the translation initiation complex and generates a double-stranded substrate for RNase III. Deletion or substitution of the motif (UCCCCUG) within icaR 3'-UTR was sufficient to abolish this interaction and resulted in the accumulation of IcaR repressor and inhibition of biofilm development. Our findings provide a singular example of a new potential post-transcriptional regulatory mechanism to modulate bacterial gene expression through the interaction of a 3'-UTR with the 5'-UTR of the same mRNA.