title: SpoVG Is a Conserved RNA-Binding Protein That RegulatesListeria monocytogenesLysozyme Resistance, Virulence, and Swarming Motility.
abstract: In this study, we sought to characterize the targets of the abundantListeria monocytogenesnoncoding RNA Rli31, which is required forL. monocytogeneslysozyme resistance and pathogenesis. Whole-genome sequencing of lysozyme-resistant suppressor strains identified loss-of-expression mutations in the promoter ofspoVG, and deletion ofspoVGrescued lysozyme sensitivity and attenuationin vivoof therli31mutant. SpoVG was demonstrated to be an RNA-binding protein that interacted with Rli31in vitro. The relationship between Rli31 and SpoVG is multifaceted, as both thespoVG-encoded protein and thespoVG5′-untranslated region interacted with Rli31. In addition, we observed thatspoVG-deficient bacteria were nonmotile in soft agar and suppressor mutations that restored swarming motility were identified in the gene encoding a major RNase in Gram-positive bacteria, RNase J1. Collectively, these findings suggest that SpoVG is similar to global posttranscriptional regulators, a class of RNA-binding proteins that interact with noncoding RNA, regulate genes in concert with RNases, and control pleiotropic aspects of bacterial physiology.
  
  
  
  spoVGis widely conserved among bacteria; however, the function of this gene has remained unclear since its initial characterization in 1977. Mutation ofspoVGimpacts various phenotypes in Gram-positive bacteria, including methicillin resistance, capsule formation, and enzyme secretion inStaphylococcus aureusand also asymmetric cell division, hemolysin production, and sporulation inBacillus subtilis. Here, we demonstrate thatspoVGmutant strains ofListeria monocytogenesare hyper-lysozyme resistant, hypervirulent, nonmotile, and misregulate genes controlling carbon metabolism. Furthermore, we demonstrate that SpoVG is an RNA-binding protein. These findings suggest that SpoVG has a role inL. monocytogenes, and perhaps in other bacteria, as a global gene regulator. Posttranscriptional gene regulators help bacteria adapt to various environments and coordinate differing aspects of bacterial physiology. SpoVG may help the organism coordinate environmental growth and virulence to survive as a facultative pathogen.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Burke
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA School of Public Health, University of California, Berkeley, Berkeley, California, USA Portnoy@berkeley.edu.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Portnoy
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial; D016680:Genome, Bacterial; D008089:Listeria monocytogenes / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D008124:Locomotion; D009113:Muramidase / Q000378:metabolism*; D009154:Mutation; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D016601:RNA-Binding Proteins; D009113:Muramidase