Magnetosomes Are Cell Membrane Invaginations Organized by the Actin-Like Protein MamK
Abstract
Magnetosomes are membranous bacterial organelles sharing many features of eukaryotic organelles. Using electron cryotomography, we found that magnetosomes are invaginations of the cell membrane flanked by a network of cytoskeletal filaments. The filaments appeared to be composed of MamK, a homolog of the bacterial actin-like protein MreB, which formed filaments in vivo. In a mamK deletion strain, the magnetosome-associated cytoskeleton was absent and individual magnetosomes were no longer organized into chains. Thus, it seems that prokaryotes can use cytoskeletal filaments to position organelles within the cell.
Additional Information
© 2005 American Association for the Advancement of Science. Received for publication 5 October 2005. Accepted for publication 12 December 2005. Published online 22 December 2005. We thank W. Tivol and G. Henderson for technical assistance, D. Morris for help with image processing, and K. Ryan for critical reading of the manuscript. This work was supported in part by NIH grant PO1 GM66521 to G.J.J., DOE grant DE-FG02-04ER63785 to G.J.J., a Searle Scholar Award to G.J.J., and gifts to Caltech from the Ralph M. Parsons Foundation, the Agouron Institute, and the Gordon and Betty Moore Foundation. D.K.N. was supported by grants from the Packard and Luce Foundations. A.K. was a Senior Research Fellow of the Beckman Institute and was supported by the Arnold and Mabel Beckman Foundation. Supporting Online Material: http://www.sciencemag.org/cgi/content/full/1123231/DC1 Materials and Methods References Movies S1 to S4Attached Files
Supplemental Material - KOMs06s1.mov
Supplemental Material - KOMs06s2.mov
Supplemental Material - KOMs06s3.mov
Supplemental Material - KOMs06s4.mov
Supplemental Material - KOMs06supp.pdf
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Additional details
- Eprint ID
- 24658
- DOI
- 10.1126/science.1123231
- Resolver ID
- CaltechAUTHORS:20110803-122522248
- PO1 GM66521
- NIH
- DE-FG02-04ER63785
- Department of Energy (DOE)
- Searle Scholars Program
- Ralph M. Parsons Foundation
- Agouron Institute
- Gordon and Betty Moore Foundation
- David and Lucile Packard Foundation
- Henry Luce Foundation
- Caltech Beckman Institute
- Arnold and Mabel Beckman Foundation
- Created
-
2011-08-03Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences