title: Involvement of membrane lipids in protein export in Escherichia coli.
abstract: Several models for the transport of proteins across membranes predict a role for lipids. If these models are correct, then alterations in lipid metabolism may affect protein export and vice versa. We are investigating this possibility by studying Escherichia coli K-12 mutants with defects in protein export or phospholipid metabolism. A temperature-sensitive secA mutant, which is defective in protein export at 42 degrees C, exhibited severe pleiotropic effects on membrane biogenesis. Incubation of this strain at 42 degrees C resulted in the appearance of intracytoplasmic membranes, in alterations in lipopolysaccharide structure and in decreased cardiolipin and C18:1 fatty acid content. On the other hand, a pgsA mutant which is defective in the synthesis of acidic phospholipids, exhibited a protein export defect when studied in vivo or in vitro. These results are in agreement with a postulated role of membrane lipids in protein export.
authors.affiliation: Department of Molecular Cell Biology, University of Utrecht, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Tommassen
authors.forename: T
authors.initials: T
authors.lastname: de Vrije
authors.forename: H
authors.initials: H
authors.lastname: de Cock
authors.forename: D
authors.initials: D
authors.lastname: Bosch
authors.forename: B
authors.initials: B
authors.lastname: de Kruijff
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001692:Biological Transport / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D008563:Membrane Lipids / Q000235:genetics / Q000502:physiology*; D009154:Mutation
chemical_list: D001426:Bacterial Proteins; D008563:Membrane Lipids