title: Origin and fate of the lysophosphatidylethanolamine in a chain-forming mutant (envC) of Escherichia coli.
abstract: The role of phospholipid metabolism in the functioning of the bacterial envelope was investigated in the chain-forming Escherichia coli envC. Lysophosphatidylethanolamine (LPE) which accumulated in this strain during growth was identified as the product of phosphatidylethanolamine (PE) hydrolysis by a phospholipase A1, i.e. 2-acylLPE. Isotopically labelled LPE transferred into intact mutant and parent cells by liposome/bacteria interaction was rapidly reacylated to PE. However, in envC the final PE/LPE ratio was lower than that in the parent, thus showing that the fate of LPE is modified. Crude cell extracts degraded LPE to a lesser extent in envC than in the parent but were unable to promote reacylation activity under our experimental conditions. In both strains, the lysophospholipase activity was neither calcium-dependent nor inhibited by the SH-group inhibitors pHMB or pCMPS, and hydrolysed 1-acylLPE as well as 2-acylLPE. These results indicate the existence of a deacylation-reacylation cycle in E. coli and show that this cycle is perturbed in envC cells, especially at the lysophospholipase step.
mesh_terms: D002473:Cell Wall / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis; D006902:Hydroxymercuribenzoates / Q000494:pharmacology; D008081:Liposomes / Q000378:metabolism; D008246:Lysophospholipids; D009154:Mutation; D010714:Phosphatidylethanolamines / Q000032:analysis / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D006902:Hydroxymercuribenzoates; D008081:Liposomes; D008246:Lysophospholipids; D010714:Phosphatidylethanolamines; C008301:lysophosphatidylethanolamine; C030601:4-hydroxymercuribenzoate