title: Activation of the Cpx phosphorelay signal transduction system in acidic phospholipid-deficient pgsA mutant cells of Escherichia coli.
abstract: The pgsA gene encodes the enzyme for the committed step in the synthesis of acidic phospholipids in Escherichia coli, and the pssA gene does the same for zwitterionic phospholipid. It has been reported that the Rcs and Cpx phosphorelay signal transduction systems are activated in pgsA- and pssA-defective mutants, respectively. In this study, we show that the Cpx system is activated also in a pgsA mutant, whereas the Rcs system was not activated in a pssA mutant. Lack of phosphatidylglycerol in pgsA mutants causes inadequate modification of lipoproteins, resulting in poor localization to the outer membrane. The outer membrane lipoprotein RcsF is necessary for the response of the Rcs system to various stimuli, and Rcs activation in pgsA mutants involves inner membrane mislocalization of this lipoprotein. The outer membrane lipoprotein NlpE, however, while necessary for the surface adhesion-induced Cpx response, was not involved in Cpx activation in the pgsA mutant.
authors.affiliation: Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Itou
authors.forename: Kouji
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hara
mesh_terms: D001426:Bacterial Proteins / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000819:agonists / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism; D009154:Mutation; D010743:Phospholipids / Q000096:biosynthesis* / Q000235:genetics; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D015398:Signal Transduction; D017855:Transferases (Other Substituted Phosphate Groups) / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; C491730:CpxP protein, E coli; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D009097:Multienzyme Complexes; D010743:Phospholipids; C489728:rcsC protein, E coli; C078611:rcsF protein, E coli; C085504:CpxR protein, Bacteria; D016695:Glycosyltransferases; C412464:PssA protein, Rhizobium leguminosarum; D011494:Protein Kinases; D017855:Transferases (Other Substituted Phosphate Groups); C020676:CDP-diacylglycerol-glycerol-3-phosphate 3-phosphatidyltransferase; D010749:Phosphoprotein Phosphatases