Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1994-3-16
pubmed:abstractText
In Escherichia coli, a functional GlpF protein is necessary for efficient uptake of glycerol at low concentrations. Here we show that GlpF-mediated glycerol uptake was sensitive to a variety of lipid alterations. Overproduction or mutation of the genes coding for enzymes involved in lipid biosynthesis resulted in changed membrane composition and fluidity. The strains with altered lipid composition had a substrate affinity for glycerol (Km) similar to that of wild-type cells, but the Vmax for glycerol uptake was affected. Experiments with glpF::lacZ and glpK::lacZ protein fusions showed that the expression of these two genes was not changed under these conditions. In addition, we observed that mutations in glpF were accompanied by reduced membrane permeability for compounds unrelated to glycerol. Passive diffusion across the membranes of glpF mutants for o-nitrophenyl galactoside was 5-fold slower than in glpF+ cells. The mutants were more resistant to the hydrophobic antibiotic tetracycline, as well as to the membrane perturbants ethanol and dimethylsulphoxide and to the stress of low-osmolarity medium.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0923-2508
pubmed:author
pubmed:issnType
Print
pubmed:volume
144
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
565-74
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Glycerol uptake in Escherichia coli is sensitive to membrane lipid composition.
pubmed:affiliation
Department of Biology, University of Konstanz, Germany.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't