title: Unphosphorylated EIIANtrinduces ClpAP-mediated degradation of RpoS in Azotobacter vinelandii.
abstract: The nitrogen-related phosphotransferase system (PTSNtr) is composed of the EINtr, NPr and EIIANtrproteins that form a phosphorylation cascade from phosphoenolpyruvate. PTSNtris a global regulatory system present in most Gram-negative bacteria that controls some pivotal processes such as potassium and phosphate homeostasis, virulence, nitrogen fixation and ABC transport activation. In the soil bacterium Azotobacter vinelandii, unphosphorylated EIIANtrnegatively regulates the expression of genes related to the synthesis of the bioplastic polyester poly-β-hydroxybutyrate (PHB) and cyst-specific lipids alkylresorcinols (ARs). The mechanism by which EIIANtrcontrols gene expression in A. vinelandii is not known. Here, we show that, in presence of unphosphorylated EIIANtr, the stability of the stationary phase sigma factor RpoS, which is necessary for transcriptional activation of PHB and ARs synthesis related genes, is reduced, and that the inactivation of genes coding for ClpAP protease complex in strains that carry unphosphorylated EIIANtr, restored the levels and in vivo stability of RpoS, as well as the synthesis of PHB and ARs. Taken together, our results reveal a novel mechanism, by which EIIANtrglobally controls gene expression in A. vinelandii, where the unphosphorylated EIIANtrinduces the degradation of RpoS by the proteolytic complex ClpAP.
authors.affiliation: Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, 62210, México.
authors.forename: Luis Felipe
authors.initials: LF
authors.lastname: Muriel-Millán
authors.affiliation: Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, 62210, México.
authors.forename: Soledad
authors.initials: S
authors.lastname: Moreno
authors.affiliation: Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, 62210, México.
authors.forename: Ramsés
authors.initials: R
authors.lastname: Gallegos-Monterrosa
authors.affiliation: Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, 62210, México.
authors.forename: Guadalupe
authors.identifier: 0000-0002-2116-144X
authors.initials: G
authors.lastname: Espín
mesh_terms: D016948:Azotobacter vinelandii / Q000235:genetics; D001426:Bacterial Proteins / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D006885:Hydroxybutyrates / Q000378:metabolism; D009586:Nitrogen Fixation; D010728:Phosphoenolpyruvate / Q000378:metabolism; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism* / Q000502:physiology; D011091:Polyesters / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D012808:Sigma Factor / Q000378:metabolism; D015533:Transcriptional Activation; D000094122:Polyhydroxybutyrates
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006885:Hydroxybutyrates; D010728:Phosphoenolpyruvate; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; D010770:Phosphotransferases; D011091:Polyesters; D011188:Potassium; D012808:Sigma Factor; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates; C529959:PtsN protein, E coli