title: Effects of the global regulator CsrA on the BarA/UvrY two-component signaling system.
abstract: The hybrid sensor kinase BarA and its cognate response regulator UvrY, members of the two-component signal transduction family, activate transcription of CsrB and CsrC noncoding RNAs. These two small RNAs act by sequestering the RNA binding protein CsrA, which posttranscriptionally regulates translation and/or stability of its target mRNAs. Here, we provide evidence that CsrA positively affects, although indirectly, uvrY expression, at both the transcriptional and translational levels. We also demonstrate that CsrA is required for properly switching BarA from its phosphatase to its kinase activity. Thus, the existence of a feedback loop mechanism that involves the Csr and BarA/UvrY global regulatory systems is exposed.
authors.affiliation: Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., México.
authors.forename: Martha I
authors.initials: MI
authors.lastname: Camacho
authors.affiliation: Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., México.
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Alvarez
authors.affiliation: Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., México.
authors.forename: Ricardo Gonzalez
authors.initials: RG
authors.lastname: Chavez
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA.
authors.forename: Tony
authors.initials: T
authors.lastname: Romeo
authors.affiliation: Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
authors.forename: Enrique
authors.initials: E
authors.lastname: Merino
authors.affiliation: Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., México dimitris@ifc.unam.mx.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Georgellis
mesh_terms: D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D010770:Phosphotransferases / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: C093587:CsrA protein, E coli; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C419603:UvrY protein, E coli; C074276:barA protein, E coli; D010770:Phosphotransferases