Secondary structure of the mRNA encoding listeriolysin O is essential to establish the replicative niche of L. monocytogenes
| Autor: | Peterson, Bret N, Portman, Jonathan L, Feng, Ying, Wang, Jeffrey, Portnoy, Daniel A |
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| Rok vydání: | 2020 |
| Předmět: |
DNA Replication
1.1 Normal biological development and functioning Messenger Bacterial Toxins translation Vaccine Related Mice Hemolysin Proteins Underpinning research Biodefense Genetics Animals 2.1 Biological and endogenous factors Listeriosis Aetiology bacteria Heat-Shock Proteins pathogenesis Prevention Bacterial Listeria monocytogenes cytolysin Infectious Diseases Emerging Infectious Diseases RNA Nucleic Acid Conformation 5' Untranslated Regions Infection |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America, vol 117, iss 38 |
| Popis: | Intracellular pathogens are responsible for an enormous amount of worldwide morbidity and mortality, and each has evolved specialized strategies to establish and maintain their replicative niche. Listeria monocytogenes is a facultative intracellular pathogen that secretes a pore-forming cytolysin called listeriolysin O (LLO), which disrupts the phagosomal membrane and, thereby, allows the bacteria access to their replicative niche in the cytosol. Nonsynonymous and synonymous mutations in a PEST-like domain near the LLO N terminus cause enhanced LLO translation during intracellular growth, leading to host cell death and loss of virulence. Here, we explore the mechanism of translational control and show that there is extensive codon restriction within the PEST-encoding region of the LLO messenger RNA (mRNA) (hly). This region has considerable complementarity with the 5' UTR and is predicted to form an extensive secondary structure that overlaps the ribosome binding site. Analysis of both 5' UTR and synonymous mutations in the PEST-like domain that are predicted to disrupt the secondary structure resulted in up to a 10,000-fold drop in virulence during mouse infection, while compensatory double mutants restored virulence to WT levels. We showed by dynamic protein radiolabeling that LLO synthesis was growth phase-dependent. These data provide a mechanism to explain how the bacteria regulate translation of LLO to promote translation during starvation in a phagosome while repressing it during growth in the cytosol. These studies also provide a molecular explanation for codon bias at the 5' end of this essential determinant of pathogenesis. |
| Databáze: | OpenAIRE |
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