title: Localisation and protein-protein interactions of the Helicobacter pylori taxis sensor TlpD and their connection to metabolic functions.
abstract: The Helicobacter pylori energy sensor TlpD determines tactic behaviour under low energy conditions and is important in vivo. We explored protein-protein interactions of TlpD and their impact on TlpD localisation and function. Pull-down of tagged TlpD identified protein interaction partners of TlpD, which included the chemotaxis histidine kinase CheAY2, the central metabolic enzyme aconitase (AcnB) and the detoxifying enzyme catalase (KatA). We confirmed that KatA and AcnB physically interact with TlpD. While the TlpD-dependent behavioural response appeared not influenced in the interactor mutants katA and acnB in steady-state behavioural assays, acetone carboxylase subunit (acxC) mutant behaviour was altered. TlpD was localised in a bipolar subcellular pattern in media of high energy. We observed a significant change in TlpD localisation towards the cell body in cheAY2-, catalase- or aconitase-deficient bacteria or in bacteria incubated under low energy conditions, including oxidative stress or respiratory inhibition. Inactivation of tlpD resulted in an increased sensitivity to iron limitation and oxidative stress and influenced the H. pylori transcriptome. Oxidative stress, iron limitation and overexpressing the iron-sulfur repair system nifSU altered TlpD-dependent behaviour. We propose that TlpD localisation is instructed by metabolic activity and protein interactions, and its sensory activity is linked to iron-sulfur cluster integrity.
authors.affiliation: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany.
authors.forename: Wiebke
authors.initials: W
authors.lastname: Behrens
authors.affiliation: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Schweinitzer
authors.affiliation: Department of Molecular &Cellular Biology, Kennesaw State University, Kennesaw, GA, USA.
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: McMurry
authors.affiliation: Department of Microbiology, University of Manitoba, Winnipeg, Canada.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Loewen
authors.affiliation: Institute for Cellular Chemistry, Hannover Medical School, Hannover, Germany.
authors.forename: Falk F R
authors.initials: FF
authors.lastname: Buettner
authors.affiliation: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Menz
authors.affiliation: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany.|German Center of Infection Research, partner site Hannover-Braunschweig, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Josenhans
mesh_terms: D000154:Aconitate Hydratase / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D002633:Chemotaxis; D015964:Gene Expression Regulation, Bacterial; D016480:Helicobacter pylori / Q000235:genetics / Q000378:metabolism*; D006706:Homeostasis; D007501:Iron / Q000737:chemistry; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D013058:Mass Spectrometry; D009154:Mutation; D018384:Oxidative Stress; D010101:Oxygen Consumption; D025941:Protein Interaction Mapping; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D007501:Iron; D002374:Catalase; C508532:katA protein, Helicobacter pylori; D000154:Aconitate Hydratase