title: Oxygen-dependent regulation of c-di-GMP synthesis by SadC controls alginate production in Pseudomonas aeruginosa.
abstract: Pseudomonas aeruginosa produces increased levels of alginate in response to oxygen-deprived conditions. The regulatory pathway(s) that links oxygen limitation to increased synthesis of alginate has remained elusive. In the present study, using immunofluorescence microscopy, we show that anaerobiosis-induced alginate production by planktonic PAO1 requires the diguanylate cyclase (DGC) SadC, previously identified as a regulator of surface-associated lifestyles. Furthermore, we found that the gene products of PA4330 and PA4331, located in a predicted operon with sadC, have a major impact on alginate production: deletion of PA4330 (odaA, for oxygen-dependent alginate synthesis activator) caused an alginate production defect under anaerobic conditions, whereas a PA4331 (odaI, for oxygen-dependent alginate synthesis inhibitor) deletion mutant produced alginate also in the presence of oxygen, which would normally inhibit alginate synthesis. Based on their sequence, OdaA and OdaI have predicted hydratase and dioxygenase reductase activities, respectively. Enzymatic assays using purified protein showed that unlike OdaA, which did not significantly affect DGC activity of SadC, OdaI inhibited c-di-GMP production by SadC. Our data indicate that SadC, OdaA and OdaI are components of a novel response pathway of P. aeruginosa that regulates alginate synthesis in an oxygen-dependent manner.
authors.affiliation: Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, 72076, Tübingen, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Schmidt
authors.affiliation: Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, 72076, Tübingen, Germany.|Bristol-Myers Squibb, Munich, Germany.
authors.forename: Anna Silke
authors.initials: AS
authors.lastname: Hammerbacher
authors.affiliation: Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, 72076, Tübingen, Germany.|Birken AG, Niefern-Öschelbronn, Germany.
authors.forename: Mike
authors.initials: M
authors.lastname: Bastian
authors.affiliation: Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, 72076, Tübingen, Germany.
authors.forename: Karen Jule
authors.initials: KJ
authors.lastname: Nieken
authors.affiliation: Clinical Research Group, 'Molecular Pathology' of Cystic Fibrosis and Pseudomonas Genomics, Hannover Medical School, 30625, Hannover, Germany.|Hannover and Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research, Hannover, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Klockgether
authors.affiliation: Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA, 02115, USA.|Ginkgo Bioworks, Boston, Massachusetts, USA.
authors.forename: Massimo
authors.initials: M
authors.lastname: Merighi
authors.affiliation: Departement of Fundamental Microbiology, University of Lausanne, 1015, Lausanne, Switzerland.|Biochemistry Center (BZH), University of Heidelberg, 69120, Heidelberg, Germany.
authors.forename: Karine
authors.initials: K
authors.lastname: Lapouge
authors.affiliation: Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, 72076, Tübingen, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Poschgan
authors.affiliation: Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, 72076, Tübingen, Germany.|University of Erlangen-Nürnberg, 91054, Erlangen, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Kölle
authors.affiliation: Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY, England.
authors.forename: K Ravi
authors.initials: KR
authors.lastname: Acharya
authors.affiliation: Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, 72076, Tübingen, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Ulrich
authors.affiliation: Clinical Research Group, 'Molecular Pathology' of Cystic Fibrosis and Pseudomonas Genomics, Hannover Medical School, 30625, Hannover, Germany.|Hannover and Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research, Hannover, Germany.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Tümmler
authors.affiliation: Institute for Microbiology and Wine Research, Johannes Gutenberg University Mainz, 55099, Mainz, Germany.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Unden
authors.affiliation: Research Core Unit Metabolomics and Institute of Pharmacology, Hannover Medical School, 30625, Hannover, Germany.
authors.forename: Volkhard
authors.initials: V
authors.lastname: Kaever
authors.affiliation: Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Lory
authors.affiliation: Departement of Fundamental Microbiology, University of Lausanne, 1015, Lausanne, Switzerland.
authors.forename: Dieter
authors.initials: D
authors.lastname: Haas
authors.affiliation: Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, 72076, Tübingen, Germany. sandra.schwarz@med.uni-tuebingen.de.
authors.forename: Sandra
authors.initials: S
authors.lastname: Schwarz
authors.affiliation: Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, 72076, Tübingen, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Döring
mesh_terms: D000464:Alginates; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D020723:Glucuronic Acid / Q000096:biosynthesis; D006603:Hexuronic Acids; D009876:Operon; D010100:Oxygen / Q000378:metabolism*; D019761:Phosphorus-Oxygen Lyases / Q000235:genetics / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism*
chemical_list: D000464:Alginates; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006603:Hexuronic Acids; C062025:bis(3',5')-cyclic diguanylic acid; D020723:Glucuronic Acid; D019761:Phosphorus-Oxygen Lyases; C060720:diguanylate cyclase; D006152:Cyclic GMP; D010100:Oxygen