title: Lipid metabolism in Chlamydia trachomatis-infected cells: directed trafficking of Golgi-derived sphingolipids to the chlamydial inclusion.
abstract: Chlamydia trachomatis undergoes its entire life cycle within an uncharacterized intracellular vesicle that does not fuse with lysosomes. We used a fluorescent Golgi-specific probe, (N-[7-(4-nitrobenzo-2-oxa-1,3-diazole)]) aminocaproylsphingosine (C6-NBD-Cer), in conjunction with conventional fluorescence or confocal microscopy to identify interactions between the Golgi apparatus and the chlamydial inclusion. We observed not only a close physical association between the Golgi apparatus and the chlamydial inclusion but the eventual presence of a metabolite of this fluorescent probe associated with the chlamydiae themselves. Sphingomyelin, endogenously synthesized from C6-NBD-Cer, was specifically transported to the inclusion and incorporated into the cell wall of the intracellular chlamydiae. Incorporation of the fluorescent sphingolipid by chlamydiae was inhibited by brefeldin A. Chlamydiae therefore occupy a vesicle distal to the Golgi apparatus that receives anterograde vesicular traffic from the Golgi normally bound for the plasma membrane. Collectively, the data suggest that the chlamydial inclusion may represent a unique compartment within the trans-Golgi network.
authors.affiliation: Host-Parasite Interactions Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, MT 59840, USA.
authors.forename: T
authors.initials: T
authors.lastname: Hackstadt
authors.forename: M A
authors.initials: MA
authors.lastname: Scidmore
authors.forename: D D
authors.initials: DD
authors.lastname: Rockey
mesh_terms: D009327:4-Chloro-7-nitrobenzofurazan / Q000031:analogs & derivatives; D002518:Ceramides; D002692:Chlamydia trachomatis / Q000472:pathogenicity / Q000502:physiology*; D002855:Chromatography, Thin Layer; D005456:Fluorescent Dyes; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D050356:Lipid Metabolism; D008055:Lipids / Q000302:isolation & purification; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D013107:Sphingolipids / Q000378:metabolism*; D013109:Sphingomyelins / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D002518:Ceramides; D005456:Fluorescent Dyes; D008055:Lipids; D013107:Sphingolipids; D013109:Sphingomyelins; C037974:N-(7-(4-nitrobenzo-2-oxa-1,3-diazole))-6-aminocaproyl sphingosine; D009327:4-Chloro-7-nitrobenzofurazan