This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
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 HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lang, C.
Right arrow Articles by Schüler, D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lang, C.
Right arrow Articles by Schüler, D.
Agricola
Right arrow Articles by Lang, C.
Right arrow Articles by Schüler, D.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, August 2008, p. 4944-4953, Vol. 74, No. 15
0099-2240/08/$08.00+0     doi:10.1128/AEM.00231-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Expression of Green Fluorescent Protein Fused to Magnetosome Proteins in Microaerophilic Magnetotactic Bacteria{triangledown} ,{dagger}

Claus Lang and Dirk Schüler*

Ludwig-Maximillians-Universität München, Department Biologie I, Bereich Mikrobiologie, Maria-Ward-Str. 1a, 80638 Munich, Germany

Received 25 January 2008/ Accepted 26 May 2008

The magnetosomes of magnetotactic bacteria are prokaryotic organelles consisting of a magnetite crystal bounded by a phospholipid bilayer that contains a distinct set of proteins with various functions. Because of their unique magnetic and crystalline properties, magnetosome particles are potentially useful as magnetic nanoparticles in a number of applications, which in many cases requires the coupling of functional moieties to the magnetosome membrane. In this work, we studied the use of green fluorescent protein (GFP) as a reporter for the magnetosomal localization and expression of fusion proteins in the microaerophilic Magnetospirillum gryphiswaldense by flow cytometry, fluorescence microscopy, and biochemical analysis. Although optimum conditions for high fluorescence and magnetite synthesis were mutually exclusive, we established oxygen-limited growth conditions, which supported growth, magnetite biomineralization, and GFP fluorophore formation at reasonable rates. Under these optimized conditions, we studied the subcellular localization and expression of the GFP-tagged magnetosome proteins MamC, MamF, and MamG by fluorescence microscopy and immunoblotting. While all fusions specifically localized at the magnetosome membrane, MamC-GFP displayed the strongest expression and fluorescence. MamC-GFP-tagged magnetosomes purified from cells displayed strong fluorescence, which was sensitive to detergents but stable under a wide range of temperature and salt concentrations. In summary, our data demonstrate the use of GFP as a reporter for protein localization under magnetite-forming conditions and the utility of MamC as an anchor for magnetosome-specific display of heterologous gene fusions.

* Corresponding author. Mailing address: Ludwig-Maximillians-Universität München, Department Biologie I, Bereich Mikrobiologie, Maria-Ward-Str. 1a, 80638 Munich, Germany. Phone: 498921806145. Fax: 498921806127. E-mail: dirk.schueler{at}lrz.uni-muenchen.de

{triangledown} Published ahead of print on 6 June 2008.

{dagger} Supplemental material for this article may be found at http://aem.asm.org/.

Applied and Environmental Microbiology, August 2008, p. 4944-4953, Vol. 74, No. 15
0099-2240/08/$08.00+0     doi:10.1128/AEM.00231-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Lang, C., Pollithy, A., Schuler, D. (2009). Identification of Promoters for Efficient Gene Expression in Magnetospirillum gryphiswaldense. Appl. Environ. Microbiol. 75: 4206-4210 [Abstract] [Full Text]  


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