This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Rönnebäumer, K.
Right arrow Articles by Bohne, W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rönnebäumer, K.
Right arrow Articles by Bohne, W.

 Previous Article  |  Next Article 

Eukaryotic Cell, June 2008, p. 1001-1008, Vol. 7, No. 6
1535-9778/08/$08.00+0     doi:10.1128/EC.00004-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

The Nascent Parasitophorous Vacuole Membrane of Encephalitozoon cuniculi Is Formed by Host Cell Lipids and Contains Pores Which Allow Nutrient Uptake{triangledown}

Karin Rönnebäumer, Uwe Gross, and Wolfgang Bohne*

Institute of Medical Microbiology, University of Göttingen, Kreuzbergring 57, Göttingen D-37075, Germany

Received 4 January 2008/ Accepted 28 March 2008

Microsporidia are obligate intracellular pathogens which enter host cells by the discharge of a hollow tube through which the sporoplasma is extruded into the host cell. Since this invasion mechanism is very different from common entry strategies, the formation of the parasitophorous vacuole (PV) in Encephalitozoon species is likely to be distinct from known principles. We investigated the origin of the nascent Encephalitozoon cuniculi PV membrane with the aid of fluorescent lipid probes. When Bodipy 500/510-C12-HPC-labeled spores were used for infection, the emerging PV membrane was unlabeled, suggesting that sporoplasma-derived lipids do not significantly contribute to the formation of the PV membrane. In contrast, when raft and nonraft microdomains of the host cell plasma membrane were selectively labeled with DiIC16 and Speedy DiO, both tracers were detectable in the nascent PV membrane shortly after infection, indicating that the bulk lipids of the PV membrane are host cell derived. Time-lapse fluorescence microscopy revealed that the formation of the PV membrane is a fast event (<1.3 s), which occurred simultaneously with the extrusion of the sporoplasma. The portion of the discharged tube which is in contact with the host cell was found to be coated with labeled host cell lipids, which might be an indication for a plasma membrane invagination at the contact site. To investigate the presence of pores in the E. cuniculi PV membrane, we microinjected fluorescent dyes of different sizes into infected host cells. A 0.5-kDa dextran as well as 0.8- to 1.1-kDa peptides could rapidly enter the PV, while a 10-kDa dextran was stably excluded from the PV lumen, indicating that the PV membrane possesses pores with an exclusion size of <10 kDa, which should allow metabolite exchange.

* Corresponding author. Mailing address: Institute of Medical Microbiology, University of Göttingen, Kreuzbergring 57, D-37075 Göttingen, Germany. Phone: 49-551-395869. Fax: 49-551-395861. E-mail: wbohne{at}gwdg.de

{triangledown} Published ahead of print on 11 April 2008.

Eukaryotic Cell, June 2008, p. 1001-1008, Vol. 7, No. 6
1535-9778/08/$08.00+0     doi:10.1128/EC.00004-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»