title: The Crc/CrcZ-CrcY global regulatory system helps the integration of gluconeogenic and glycolytic metabolism in Pseudomonas putida.
abstract: In metabolically versatile bacteria, carbon catabolite repression (CCR) facilitates the preferential assimilation of the most efficient carbon sources, improving growth rates and fitness. In Pseudomonas putida, the Crc and Hfq proteins and the CrcZ and CrcY small RNAs, which are believed to antagonize Crc/Hfq, are key players in CCR. Unlike that seen in other bacterial species, succinate and glucose elicit weak CCR in this bacterium. In the present work, metabolic, transcriptomic and constraint-based metabolic flux analyses were combined to clarify whether P. putida prefers succinate or glucose, and to identify the role of the Crc protein in the metabolism of these compounds. When provided simultaneously, succinate was consumed faster than glucose, although both compounds were metabolized. CrcZ and CrcY levels were lower when both substrates were present than when only one was provided, suggesting a role for Crc in coordinating metabolism of these compounds. Flux distribution analysis suggested that, when both substrates are present, Crc works to organize a metabolism in which carbon compounds flow in opposite directions: from glucose to pyruvate, and from succinate to pyruvate. Thus, our results support that Crc not only favours the assimilation of preferred compounds, but balances carbon fluxes, optimizing metabolism and growth.
authors.affiliation: Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, Madrid, 28049, Spain.
authors.forename: Ruggero
authors.initials: R
authors.lastname: La Rosa
authors.affiliation: Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, Madrid, 28040, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Nogales
authors.affiliation: Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, Madrid, 28049, Spain.
authors.forename: Fernando
authors.identifier: http://orcid.org/0000-0003-1848-7745
authors.initials: F
authors.lastname: Rojo
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism*; D057465:Catabolite Repression / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005943:Gluconeogenesis / Q000235:genetics*; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis / Q000235:genetics*; D035001:Host Factor 1 Protein / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016958:Pseudomonas putida / Q000235:genetics / Q000378:metabolism*; D019289:Pyruvic Acid / Q000378:metabolism; D058727:RNA, Small Untranslated / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D019802:Succinic Acid / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D035001:Host Factor 1 Protein; D058727:RNA, Small Untranslated; D012097:Repressor Proteins; C101896:crc protein, Pseudomonas; D002244:Carbon; D019289:Pyruvic Acid; D019802:Succinic Acid; D005947:Glucose