title: Investigation of in vivo cross-talk between key two-component systems of Escherichia coli.
abstract: Intracellular signal transfer in bacteria is dominated by phosphoryl transfer between conserved transmitter and receiver domains in regulatory proteins of so-called two-component systems. Escherichia coli contains 30 such systems, which allow it to modulate gene expression, enzyme activity and the direction of flagellar rotation. The authors have investigated whether, and to what extent, these separate systems form (an) interacting network(s) in vivo, focussing on interactions between four major systems, involved in the responses to the availability of phosphorylated sugars (Uhp), phosphate (Pho), nitrogen (Ntr) and oxygen (Arc). Significant cross-talk was not detectable in wild-type cells. Decreasing expression levels of succinate dehydrogenase (reporting Arc activation), upon activation of the Pho system, appeared to be independent of signalling through PhoR. Cross-talk towards NtrC did occur, however, in a ntrB deletion strain, upon joint activation of Pho, Ntr and Uhp. UhpT expression was demonstrated when cells were grown on pyruvate, through non-cognate phosphorylation of UhpA by acetyl phosphate.
authors.affiliation: Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands1.
authors.forename: Daniël T
authors.initials: DT
authors.lastname: Verhamme
authors.affiliation: Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands1.
authors.forename: Jos C
authors.initials: JC
authors.lastname: Arents
authors.affiliation: Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands1.
authors.forename: Pieter W
authors.initials: PW
authors.lastname: Postma
authors.affiliation: Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands1.
authors.forename: Wim
authors.initials: W
authors.lastname: Crielaard
authors.affiliation: Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands1.
authors.forename: Klaas J
authors.initials: KJ
authors.lastname: Hellingwerf
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D009584:Nitrogen / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D010766:Phosphorylation; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D010710:Phosphates; C489848:UhpA protein, E coli; C080370:UhpA protein, Bacteria; D009584:Nitrogen; D010100:Oxygen