title: Growth-related Metabolism of the Carbon Storage Poly-3-hydroxybutyrate in Legionella pneumophila.
abstract: Legionella pneumophila, the causative agent of Legionnaires disease, has a biphasic life cycle with a switch from a replicative to a transmissive phenotype. During the replicative phase, the bacteria grow within host cells in Legionella-containing vacuoles. During the transmissive phenotype and the postexponential (PE) growth phase, the pathogens express virulence factors, become flagellated, and leave the Legionella-containing vacuoles. Using (13)C labeling experiments, we now show that, under in vitro conditions, serine is mainly metabolized during the replicative phase for the biosynthesis of some amino acids and for energy generation. During the PE phase, these carbon fluxes are reduced, and glucose also serves as an additional carbon substrate to feed the biosynthesis of poly-3-hydroxybuyrate (PHB), an essential carbon source for transmissive L. pneumophila. Whole-cell FTIR analysis and comparative isotopologue profiling further reveal that a putative 3-ketothiolase (Lpp1788) and a PHB polymerase (Lpp0650), but not enzymes of the crotonyl-CoA pathway (Lpp0931-0933) are involved in PHB metabolism during the PE phase. However, the data also reflect that additional bypassing reactions for PHB synthesis exist in agreement with in vivo competition assays using Acanthamoeba castellannii or human macrophage-like U937 cells as host cells. The data suggest that substrate usage and PHB metabolism are coordinated during the life cycle of the pathogen.
authors.affiliation: From the Lehrstuhl für Biochemie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Gillmaier
authors.affiliation: Working group "Cellular Interactions of Bacterial Pathogens," ZBS 2, Robert Koch-Institute, Seestrasse 10, 13353 Berlin, Germany, and.
authors.forename: Eva
authors.initials: E
authors.lastname: Schunder
authors.affiliation: From the Lehrstuhl für Biochemie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany.
authors.forename: Erika
authors.initials: E
authors.lastname: Kutzner
authors.affiliation: Working group "Cellular Interactions of Bacterial Pathogens," ZBS 2, Robert Koch-Institute, Seestrasse 10, 13353 Berlin, Germany, and.
authors.forename: Hana
authors.initials: H
authors.lastname: Tlapák
authors.affiliation: Working group "Cellular Interactions of Bacterial Pathogens," ZBS 2, Robert Koch-Institute, Seestrasse 10, 13353 Berlin, Germany, and.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Rydzewski
authors.affiliation: Working group "Cellular Interactions of Bacterial Pathogens," ZBS 2, Robert Koch-Institute, Seestrasse 10, 13353 Berlin, Germany, and.
authors.forename: Vroni
authors.initials: V
authors.lastname: Herrmann
authors.affiliation: ZBS 6 "Proteomics and Spectroscopy," Robert Koch-Institute, Nordufer 20, 13353 Berlin, Germany.
authors.forename: Maren
authors.initials: M
authors.lastname: Stämmler
authors.affiliation: ZBS 6 "Proteomics and Spectroscopy," Robert Koch-Institute, Nordufer 20, 13353 Berlin, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Lasch
authors.affiliation: From the Lehrstuhl für Biochemie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany, wolfgang.eisenreich@ch.tum.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Eisenreich
authors.affiliation: Working group "Cellular Interactions of Bacterial Pathogens," ZBS 2, Robert Koch-Institute, Seestrasse 10, 13353 Berlin, Germany, and heunerk@rki.de.
authors.forename: Klaus
authors.initials: K
authors.lastname: Heuner
mesh_terms: D053898:Biosynthetic Pathways; D045744:Cell Line, Tumor; D005947:Glucose / Q000378:metabolism; D006801:Humans; D006885:Hydroxybutyrates / Q000378:metabolism*; D016952:Legionella pneumophila / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D011091:Polyesters / Q000378:metabolism*; D000091402:Prohibitins; D012694:Serine / Q000378:metabolism; D000094122:Polyhydroxybutyrates
chemical_list: D005947:Glucose; D006885:Hydroxybutyrates; D011091:Polyesters; D000091402:Prohibitins; D012694:Serine; C000717328:PHB protein, human; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates
keywords: Legionella; biosynthesis; isotopic tracer; lipid metabolism; metabolism; pathogenesis; polyhydroxybutyrate