title: The Escherichia coli Envelope Stress Sensor CpxA Responds to Changes in Lipid Bilayer Properties.
abstract: The Cpx stress response system is induced by various environmental and cellular stimuli. It is also activated in Escherichia coli strains lacking the major phospholipid, phosphatidylethanolamine (PE). However, it is not known whether CpxA directly senses changes in the lipid bilayer or the presence of misfolded proteins due to the lack of PE in their membranes. To address this question, we used an in vitro reconstitution system and vesicles with different lipid compositions to track modulations in the activity of CpxA in different lipid bilayers. Moreover, the Cpx response was validated in vivo by monitoring expression of a PcpxP-gfp reporter in lipid-engineered strains of E. coli. Our combined data indicate that CpxA responds specifically to different lipid compositions.
authors.affiliation: †Department of Pharmacy and Biochemistry, Johannes Gutenberg-University, D-55128 Mainz, Germany.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Keller
authors.affiliation: ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Candan
authors.initials: C
authors.lastname: Ariöz
authors.affiliation: §Department of Microbiology, University of Osnabrück, D-49076 Osnabrück, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Hansmeier
authors.affiliation: ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Filippa
authors.initials: F
authors.lastname: Stenberg-Bruzell
authors.affiliation: ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Malin
authors.initials: M
authors.lastname: Burstedt
authors.affiliation: ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: David
authors.initials: D
authors.lastname: Vikström
authors.affiliation: ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Amelie
authors.initials: A
authors.lastname: Kelly
authors.affiliation: ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Åke
authors.initials: Å
authors.lastname: Wieslander
authors.affiliation: ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Daley
authors.affiliation: ∥Molecular Microbiology, University of Osnabrück, D-49076 Osnabrück, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Hunke
mesh_terms: D000128:Acholeplasma laidlawii / Q000201:enzymology / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002308:Cardiolipins / Q000737:chemistry / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017930:Genes, Reporter; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D010714:Phosphatidylethanolamines / Q000737:chemistry* / Q000378:metabolism; D010715:Phosphatidylglycerols / Q000737:chemistry / Q000378:metabolism; D010766:Phosphorylation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011494:Protein Kinases / Q000737:chemistry* / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D013499:Surface Properties
chemical_list: D001426:Bacterial Proteins; D002308:Cardiolipins; C491730:CpxP protein, E coli; D029968:Escherichia coli Proteins; D008051:Lipid Bilayers; D008565:Membrane Proteins; D010714:Phosphatidylethanolamines; D010715:Phosphatidylglycerols; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C085504:CpxR protein, Bacteria; D016695:Glycosyltransferases; D011494:Protein Kinases; C490475:CpxA protein, E coli