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 Google Scholar
Google Scholar
Right arrow Articles by Epstein, E. A.
Right arrow Articles by Chapman, M. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Epstein, E. A.
Right arrow Articles by Chapman, M. R.

 Previous Article  |  Next Article 

Journal of Bacteriology, January 2009, p. 608-615, Vol. 191, No. 2
0021-9193/09/$08.00+0     doi:10.1128/JB.01244-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Spatial Clustering of the Curlin Secretion Lipoprotein Requires Curli Fiber Assembly {triangledown} ,{dagger}

Elisabeth Ashman Epstein, Margeaux A. Reizian, and Matthew R. Chapman*

Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 North University, Ann Arbor, Michigan 48109

Received 5 September 2008/ Accepted 3 November 2008

Gram-negative bacteria assemble functional amyloid surface fibers called curli. CsgB nucleates the major curli subunit protein, CsgA, into a self-propagating amyloid fiber on the cell surface. The CsgG lipoprotein is sufficient for curlin transport across the outer membrane and is hypothesized to be the central molecule of the curli fiber secretion and assembly complex. We tested the hypothesis that the curli secretion protein, CsgG, was restricted to certain areas of the cell to promote the interaction of CsgA and CsgB during curli assembly. Here, electron microscopic analysis of curli-producing strains showed that relatively few cells in the population contacted curli fibers and that curli emanated from spatially discrete points on the cell surface. Microscopic analysis revealed that CsgG was surface exposed and spatially clustered around curli fibers. CsgG localization to the outer membrane and exposure of the surface domain were not dependent on any other csg-encoded protein, but the clustering of CsgG required the csg-encoded proteins CsgE, CsgF, CsgA, and CsgB. CsgG formed stable oligomers in all the csg mutant strains, but these oligomers were distinct from the CsgG complexes assembled in wild-type cells. Finally, we found that efficient fiber assembly was required for the spatial clustering of CsgG. These results suggest a new model where curli fiber formation is spatially coordinated with the CsgG assembly apparatus.

* Corresponding author. Mailing address: Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 North University, Ann Arbor, MI 48109. Phone: (734) 764-7592. Fax: (734) 647-0884. E-mail: chapmanm{at}umich.edu

{triangledown} Published ahead of print on 14 November 2008.

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

Journal of Bacteriology, January 2009, p. 608-615, Vol. 191, No. 2
0021-9193/09/$08.00+0     doi:10.1128/JB.01244-08
Copyright © 2009, 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»