title: Dephosphorylated NPr is involved in an envelope stress response of Escherichia coli.
abstract: Besides the canonical phosphoenolpyruvate-dependent phosphotransferase system (PTS) for carbohydrate transport, most Proteobacteria possess the so-called nitrogen PTS (PTS(Ntr)) that transfers a phosphate group from phosphoenolpyruvate (PEP) over enzyme I(Ntr) (EI(Ntr)) and NPr to enzyme IIA(Ntr) (EIIA(Ntr)). The PTS(Ntr) lacks membrane-bound components and functions exclusively in a regulatory capacity. While EIIA(Ntr) has been implicated in a variety of cellular processes such as potassium homeostasis, phosphate starvation, nitrogen metabolism, carbon metabolism, regulation of ABC transporters and poly-β-hydroxybutyrate accumulation in many Proteobacteria, the only identified role of NPr is the regulation of biosynthesis of the lipopolysaccharide (LPS) layer by direct interaction with LpxD in Escherichia coli. In this study, we provide another phenotype related to NPr. Several lines of evidence demonstrate that E. coli strains with increased levels of dephosphorylated NPr are sensitive to envelope stresses, such as osmotic, ethanol and SDS stresses, and these phenotypes are independent of LpxD. The C-terminal region of NPr plays an important role in sensitivity to envelope stresses. Thus, our data suggest that the dephospho-form of NPr affects adaptation to envelope stresses through a C-terminus-dependent mechanism.
authors.affiliation: Department of Biological Sciences, Myongji University, Yongin, Gyeonggido 449-728, Republic of Korea.
authors.forename: Jaeseop
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Young-Ha
authors.initials: YH
authors.lastname: Park
authors.affiliation: Department of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Yeon-Ran
authors.initials: YR
authors.lastname: Kim
authors.affiliation: Department of Biophysics and Chemical Biology, Seoul National University, Seoul 151-742, Republic of Korea.|Department of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Yeong-Jae
authors.initials: YJ
authors.lastname: Seok
authors.affiliation: Department of Biological Sciences, Myongji University, Yongin, Gyeonggido 449-728, Republic of Korea.
authors.forename: Chang-Ro
authors.initials: CR
authors.lastname: Lee
mesh_terms: D000217:Acyltransferases / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism; D033902:Periplasmic Binding Proteins / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D028044:Phosphate-Binding Proteins; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; D010766:Phosphorylation; D013312:Stress, Physiological
chemical_list: D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C502371:NPr protein, E coli; D033902:Periplasmic Binding Proteins; D028044:Phosphate-Binding Proteins; C074783:osmY protein, E coli; D000217:Acyltransferases; C050304:acyl-(acyl-carrier-protein)-UDP-N-acetylglucosamine acyltransferase; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; D009584:Nitrogen