title: Requirement of the RNA-binding protein SmpB during intracellular growth of Listeria monocytogenes.
abstract: Bacterial trans-translation is the main quality control mechanism employed to relieve stalled ribosomes. Trans-translation is mediated by the small protein B (SmpB) and transfer-mRNA (tmRNA) ribonucleoprotein complex, which interacts with translational complexes stalled at the 3' end of non-stop mRNAs to release the stalled ribosomes thereby targeting the nascent polypeptides and truncated mRNAs for degradation. The trans-translation system exists with a few exceptions in all bacteria. In the present study, we assessed the contribution of SmpB to the growth and virulence of Listeria monocytogenes, a human intracellular food-borne pathogen that colonizes host tissues to cause severe invasive infections. A smpB knockout significantly decreased the intracellular growth rate of L. monocytogenes during infection of murine macrophages. In addition, the mutant strain was attenuated for virulence when examined with the Galleria mellonella larvae killing assay and the organ colonisation model of mice following infection. Proteomic analysis of whole cell extracts of ΔsmpB deletion mutant revealed elevated protein levels of several proteins involved in ribosome assembly and interaction with tRNA substrates. These included the elongation factor Tu [EF-Tu] which promotes the GTP-dependent binding of aminoacyl-tRNA to the A-site of ribosomes during protein biosynthesis as well as the CysK which is known to interact with bacterial toxins that cleave tRNA substrates. The data presented here shed light on the role of SmpB and trans-translation during intracellular growth of L. monocytogenes.
authors.affiliation: Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany. Electronic address: mobarak.mraheil@mikrobio.med.uni-giessen.de.
authors.forename: Mobarak Abu
authors.initials: MA
authors.lastname: Mraheil
authors.affiliation: Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany.
authors.forename: Renate
authors.initials: R
authors.lastname: Frantz
authors.affiliation: Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany.
authors.forename: Lisa
authors.initials: L
authors.lastname: Teubner
authors.affiliation: Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Wendt
authors.affiliation: Department of Chemistry, and LOEWE-Center for Synthetic Microbiology Core Facility for Mass Spectrometry, Philipps-University Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Linne
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
authors.forename: Jessica
authors.initials: J
authors.lastname: Wingerath
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wirth
authors.affiliation: Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany.
authors.forename: Trinad
authors.initials: T
authors.lastname: Chakraborty
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D055786:Gene Knockout Techniques; D007814:Larva / Q000382:microbiology / Q000502:physiology; D007915:Lepidoptera; D008089:Listeria monocytogenes / Q000235:genetics / Q000254:growth & development* / Q000472:pathogenicity*; D008088:Listeriosis / Q000382:microbiology*; D008264:Macrophages / Q000382:microbiology; D008810:Mice, Inbred C57BL; D020543:Proteome / Q000032:analysis; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D016019:Survival Analysis
chemical_list: D020543:Proteome; D016601:RNA-Binding Proteins; C430328:small protein B
keywords: Listeria monocytogenes; SmpB; Trans-translation