title: Adaptive Remodeling of the Bacterial Proteome by Specific Ribosomal Modification Regulates Pseudomonas Infection and Niche Colonisation.
abstract: Post-transcriptional control of protein abundance is a highly important, underexplored regulatory process by which organisms respond to their environments. Here we describe an important and previously unidentified regulatory pathway involving the ribosomal modification protein RimK, its regulator proteins RimA and RimB, and the widespread bacterial second messenger cyclic-di-GMP (cdG). Disruption of rimK affects motility and surface attachment in pathogenic and commensal Pseudomonas species, with rimK deletion significantly compromising rhizosphere colonisation by the commensal soil bacterium P. fluorescens, and plant infection by the pathogens P. syringae and P. aeruginosa. RimK functions as an ATP-dependent glutamyl ligase, adding glutamate residues to the C-terminus of ribosomal protein RpsF and inducing specific effects on both ribosome protein complement and function. Deletion of rimK in P. fluorescens leads to markedly reduced levels of multiple ribosomal proteins, and also of the key translational regulator Hfq. In turn, reduced Hfq levels induce specific downstream proteomic changes, with significant increases in multiple ABC transporters, stress response proteins and non-ribosomal peptide synthetases seen for both ΔrimK and Δhfq mutants. The activity of RimK is itself controlled by interactions with RimA, RimB and cdG. We propose that control of RimK activity represents a novel regulatory mechanism that dynamically influences interactions between bacteria and their hosts; translating environmental pressures into dynamic ribosomal changes, and consequently to an adaptive remodeling of the bacterial proteome.
authors: Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom.
authors: Richard H
authors: RH
authors: Little
authors: Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom.|School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom.
authors: Lucia
authors: L
authors: Grenga
authors: Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom.
authors: Gerhard
authors: G
authors: Saalbach
authors: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom.
authors: Alexandra M
authors: AM
authors: Howat
authors: Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom.|The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom.
authors: Sebastian
authors: S
authors: Pfeilmeier
authors: Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom.
authors: Eleftheria
authors: E
authors: Trampari
authors: Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom.|School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom.
authors: Jacob G
authors: JG
authors: Malone
mesh_terms: D000222:Adaptation, Physiological; D001426:Bacterial Proteins / Q000378:metabolism*; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008954:Models, Biological; D009068:Movement; D009154:Mutation / Q000235:genetics; D018517:Plant Roots / Q000382:microbiology; D011485:Protein Binding; D020543:Proteome / Q000378:metabolism*; D011549:Pseudomonas / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D011552:Pseudomonas Infections / Q000378:metabolism* / Q000382:microbiology; D018085:Regulon / Q000235:genetics; D058441:Rhizosphere; D012270:Ribosomes / Q000378:metabolism*; D015290:Second Messenger Systems; D014908:Triticum / Q000382:microbiology; D015854:Up-Regulation / Q000235:genetics; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D020543:Proteome; C062025:bis(3',5')-cyclic diguanylic acid; D006152:Cyclic GMP