scholarly journals Effect of phospholipid composition on activity of sodium-dependent leucine transport system in Pseudomonas aeruginosa.

1986 ◽  
Vol 261 (12) ◽  
pp. 5450-5454
Author(s):  
Y Uratani ◽  
A Aiyama
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Transport System ◽  
Phospholipid Composition ◽  
Sodium Dependent ◽  
Leucine Transport

scholarly journals Nucleotide sequence and functional properties of a sodium-dependent citrate transport system from Klebsiella pneumoniae.

1992 ◽  
Vol 267 (13) ◽  
pp. 8971-8976
Author(s):  
M.E. van der Rest ◽  
R.M. Siewe ◽  
T Abee ◽  
E Schwarz ◽  
D Oesterhelt ◽  
...  
Keyword(s):  
Nucleotide Sequence ◽  
Klebsiella Pneumoniae ◽  
Functional Properties ◽  
Transport System ◽  
Citrate Transport ◽  
Sodium Dependent

A noninducible cystine transport system in rat alveolar type II cells

1995 ◽  
Vol 268 (1) ◽  
pp. L21-L26 ◽  
Author(s):  
D. M. Bukowski ◽  
S. M. Deneke ◽  
R. A. Lawrence ◽  
S. G. Jenkinson
Keyword(s):  
Transport System ◽  
Cell Types ◽  
Lung Epithelial Cells ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lung Epithelial ◽  
Sodium Dependent ◽  
Type Ii Cell ◽  
Rate Limiting

Type II lung epithelial cells are different from other lung cell types in their means of processing and regulating intracellular glutathione (GSH) levels. In lung cell types, including endothelial cells, fibroblasts, smooth muscle cells, and macrophages, oxidants, sulfhydryl reagents, and electrophilic agents have been shown to induce cystine uptake and concomitantly increase GSH levels, suggesting that cysteine, formed by intracellular reduction of cystine, is a rate-limiting substrate for GSH synthesis. The cystine transport increase was reportedly due to increase in activity of a sodium-independent transport system designated xc-. We have now examined cultures of rat lung type II cells exposed to diethylmaleic acid and arsenite. Although a rise in cellular GSH occurred, cystine transport was not induced. Cystine transport in type II cells was found to differ from the xc- system previously described. Type II cell cystine transport is primarily sodium dependent and is inhibitable by aspartate as well as glutamate and homocysteate. We conclude that the type II cell differs from other lung cell types in both its cystine transport mechanism and method of GSH regulation.

scholarly journals Membrane phospholipid composition of Pseudomonas aeruginosa grown in a cystic fibrosis mucus-mimicking medium

2021 ◽  
Vol 1863 (1) ◽  
pp. 183482
Author(s):  
Estelle Deschamps ◽  
Annick Schaumann ◽  
Isabelle Schmitz-Afonso ◽  
Carlos Afonso ◽  
Emmanuelle Dé ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Phospholipid Composition ◽  
Membrane Phospholipid

Modulation of quorum sensing in Pseudomonas aeruginosa through alteration of membrane properties

Microbiology ◽  
2005 ◽  
Vol 151 (8) ◽  
pp. 2529-2542 ◽  
Author(s):  
Christine Baysse ◽  
Méabh Cullinane ◽  
Valérie Dénervaud ◽  
Elizabeth Burrowes ◽  
J. Maxwell Dow ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Membrane Fluidity ◽  
Environmental Conditions ◽  
Adaptive Response ◽  
Environmental Changes ◽  
Membrane Lipids ◽  
Phospholipid Composition ◽  
Genetically Engineered ◽  
Membrane Properties

Changes in the cellular envelope are major physiological adaptations that occur when micro-organisms encounter extreme environmental conditions. An appropriate degree of membrane fluidity is crucial for survival, and alteration of membrane lipids is an essential adaptive response. Emerging data suggest that microbial cells may recognize alterations in their membrane viscosity resulting from certain environmental changes as a trigger for adaptive cellular responses. In Pseudomonas aeruginosa, the quorum-sensing (QS) system involves a complex regulatory circuitry that coordinates the expression of genes according to a critical population density. Interestingly, it has been shown that the QS system of P. aeruginosa can also be activated by nutritional stress, independently of the cell density, and therefore may be part of a more general adaptive response to stressful environmental conditions. In order to examine the proposed link between membrane properties and stress signalling, the effects of genetically engineered alterations of the membrane phospholipid composition of P. aeruginosa PAO1 on the activation of the stringent response and the QS system were examined. The lptA gene encoding a functional homologue of PlsC, an Escherichia coli enzyme that catalyses the second step of the phospholipid biosynthesis pathway, was identified and disrupted. Inactivation of lptA altered the fatty acid profile of phospholipids and the membrane properties, resulting in decreased membrane fluidity. This resulted in a premature production of the QS signals N-butanoyl- and N-hexanoyl-homoserine lactone (C4-HSL and C6-HSL) and a repression of 2-heptyl-3-hydroxy-4-quinolone (PQS) synthesis at later growth phases. The effects on C4- and C6-HSL depended upon the expression of relA, encoding the (p)ppGpp alarmone synthase, which was increased in the lptA mutant. Together, the findings support the concept that alterations in membrane properties can act as a trigger for stress-related gene expression.

Substrate specificity of the high-affinity glucose transport system of Pseudomonas aeruginosa

1993 ◽  
Vol 39 (7) ◽  
pp. 722-725 ◽  
Author(s):  
John L. Wylie ◽  
Elizabeth A. Worobec
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Glucose Transport ◽  
Transport System ◽  
Binding Protein ◽  
High Affinity ◽  
Glucose Binding ◽  
Glucose Transport System ◽  
Glucose Binding Protein

Specificity of the high-affinity glucose transport system of Pseudomonas aeruginosa was examined. At a concentration of [14C]glucose near the Vmax of the system, inhibition by maltose, galactose, and xylose was detected. This inhibition is similar to that detected in earlier in vivo studies and correlates with the known specificity of OprB, a glucose-specific porin of P. aeruginosa. At a level of [14C]glucose 100 times lower, only unlabelled glucose inhibited uptake to any extent. This matches the known in vitro specificity of the periplasmic glucose binding protein. These findings were used to explain the discrepancy between earlier in vivo and in vitro results reported in the literature.Key words: Pseudomonas aeruginosa, glucose transport, OprB, glucose binding protein.

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