|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Journal of Lipid Research, Vol. 49, 746-762, April 2008
Copyright © 2008 by American Society for Biochemistry and Molecular Biology














* Unité Mixte de Recherche 5168, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Institut National de la Recherche Agronomique-Université Joseph Fourier, Institut de Recherches en Technologies et Sciences pour le Vivant, 38058 Grenoble, France
Unité Mixte de Recherche 5163, Centre National de la Recherche Scientifique-Université Joseph Fourier, Institut Jean Roget, Campus Santé, 38042 Grenoble, France
Unité Mixte de Recherche 5235, Centre National de la Recherche Scientifique-Institut National de la Santé et de la Recherche Médicale-Université Montpellier II, 34095 Montpellier, France
** Departamento de Bioquímica, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, Distrito Federal, México

Division of Biology, Kansas State University, Kansas Lipidomics Research Center, Manhattan, KS 66506-4901

Department of Ophthalmology and Visual Sciences, Pediatrics (Infectious Diseases), Pathology, and Committees on Genetics, Molecular Medicine, and Immunology, University of Chicago, Chicago, IL 60637
Published, JLR Papers in Press, January 8, 2008.
1 To whom correspondence should be addressed. e-mail: corinne.mercier{at}ujf-grenoble.fr (C.M.); eric.marechal{at}cea.fr (E.M.)
Toxoplasma gondii is a unicellular parasite characterized by unique extracellular and intracellular membrane compartments. The lipid composition of subcellular membranes has not been determined, limiting our understanding of lipid homeostasis, control, and trafficking, a series of processes involved in pathogenesis. In addition to a mitochondrion, Toxoplasma contains a plastid called the apicoplast. The occurrence of a plastid raised the question of the presence of chloroplast galactolipids. Using three independent rabbit and rat antibodies against digalactosyldiacylglycerol (DGDG) from plant chloroplasts, we detected a class of Toxoplasma lipids harboring a digalactolipid-like epitope (DGLE). Immunolabeling characterization supports the notion that the DGLE polar head is similar to that of DGDG. Mass spectrometry analyses indicated that dihexosyl lipids having various hydrophobic moieties (ceramide, diacylglycerol, and acylalkylglycerol) might react with anti-DGDG, but we cannot exclude the possibility that more complex dihexosyl-terminated lipids might also be immunolabeled. DGLE localization was analyzed by immunofluorescence and immunoelectron microscopy and confirmed by subcellular fractionation. No immunolabeling of the apicoplast could be observed. DGLE was scattered in pellicle membrane domains in extracellular tachyzoites and was relocalized to the anterior tip of the cell upon invasion in an actin-dependent manner, providing insights on a possible role in pathogenetic processes. DGLE was detected in other Apicomplexa (i.e., Neospora, Plasmodium, Babesia, and Cryptosporidium).
Supplementary key words Apicomplexa galactolipids digalactosyldiacylglcycerol inner membrane complex membrane domains
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Journal of Biological Chemistry |
| Molecular and Cellular Proteomics | ASBMB Today |