title: The role of apolipoprotein N-acyl transferase, Lnt, in the lipidation of factor H binding protein of Neisseria meningitidis strain MC58 and its potential as a drug target.
abstract: OBJECTIVE
  The level of cell surface expression of the meningococcal vaccine antigen, Factor H binding protein (FHbp) varies between and within strains and this limits the breadth of strains that can be targeted by FHbp-based vaccines. The molecular pathway controlling expression of FHbp at the cell surface, including its lipidation, sorting to the outer membrane and export, and the potential regulation of this pathway have not been investigated until now. This knowledge will aid our evaluation of FHbp vaccines.
  
  
  METHODS
  A meningococcal transposon library was screened by whole cell immuno-dot blotting using an anti-FHbp antibody to identify a mutant with reduced binding and the disrupted gene was determined.
  
  
  RESULTS
  In a mutant with markedly reduced binding, the transposon was located in the lnt gene which encodes apolipoprotein N-acyl transferase, Lnt, responsible for the addition of the third fatty acid to apolipoproteins prior to their sorting to the outer membrane. We provide data indicating that in the Lnt mutant, FHbp is diacylated and its expression within the cell is reduced 10 fold, partly due to inhibition of transcription. Furthermore the Lnt mutant showed 64 fold and 16 fold increase in susceptibility to rifampicin and ciprofloxacin respectively.
  
  
  CONCLUSIONS
  We speculate that the inefficient sorting of diacylated FHbp in the meningococcus results in its accumulation in the periplasm inducing an envelope stress response to down-regulate its expression. We propose Lnt as a potential novel drug target for combination therapy with antibiotics.
  
  
  BACKGROUND
  This article is part of a themed section on Drug Metabolism and Antibiotic Resistance in Micro-organisms. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.14/issuetoc.
authors: School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, UK.
authors: R A G
authors: RAG
authors: da Silva
authors: School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, UK.
authors: C P
authors: CP
authors: Churchward
authors: School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, UK.
authors: A V
authors: AV
authors: Karlyshev
authors: School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, UK.
authors: O
authors: O
authors: Eleftheriadou
authors: School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, UK.
authors: A K
authors: AK
authors: Snabaitis
authors: School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, UK.
authors: M R
authors: MR
authors: Longman
authors: School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, UK.
authors: A
authors: http://orcid.org/0000-0002-4627-8185
authors: A
authors: Ryan
authors: School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, UK.
authors: R
authors: R
authors: Griffin
mesh_terms: D000217:Acyltransferases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000942:Antigens, Bacterial / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D002939:Ciprofloxacin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D009154:Mutation; D009345:Neisseria meningitidis / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D012293:Rifampin / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004791:Enzyme Inhibitors; C484699:factor H-binding protein, Neisseria meningitidis; D002939:Ciprofloxacin; D000217:Acyltransferases; C068902:apolipoprotein N-acyltransferase; D012293:Rifampin