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Joseph Pogliano e-mail: jpoglian@biomail.ucsd.edu |
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Evolution of the microbial cytoskeleton
Prokaryotic cells have a complex subcellular organization but how this organization is established and maintained remains poorly understood due to our limited knowledge of the proteins that make up the prokaryotic cytoskeleton. The goals of my lab are to identify and characterize the major families of dynamic cytoskeletal proteins that exist in bacteria, to determine the various functions that they perform, and to understand how these polymers are regulated spatially and temporally by other factors within the cell. My lab specializes in using genetics and cell biology to study the function and in vivo assembly dynamics of cytoskeletal polymers in many different species of prokaryotes, including E. coli, Bacillus subtillis, B. megaterium, B. thuringiensis, Mycobacterium smegmatis, and Pseudomonas species. Our approach has been to focus on bacterial plasmids as tools to discover new families of cytoskeletal polymers. Plasmids offer the advantages that they are genetically diverse and each encodes its own segregation system. Our studies have led to the discovery of new types of cytoskeletal structures involved in DNA segregation in bacteria (Pogliano 2008), including a new family of tubulins (TubZ) (Larsen et al. 2007) and a new family of actins (AlfA) (Becker et al. 2006). To complete some of our long term goals, we have initiated collaborations with biochemists, structural biologists and physicists to study polymer assembly in vitro and in silico to generate an integrated and detailed mechanistic understanding of cytoskeletal dynamics in prokaryotes. Studies of the bacterial cytoskeleton will lead to an understanding of how prokaryotic cells generate and maintain their subcellular organization and will provide insight into how the eukaryotic cytoskeleton evolved.
Image of sporulating Bacillus megaterium with membranes stained red with FM 4-64.
Becker, E., Herrera, N.C., Gunderson, F.Q., Derman, A.I., Dance, A.L., Sims, J., Larsen, R.A., and Pogliano, J. 2006. DNA segregation by the bacterial actin AlfA during Bacillus subtilis growth and development. EMBO J. 25(24):5919-5931.
Derman, A.I., Lim-Fong, G., and Pogliano, J. 2008. Intracellular mobility of plasmid DNA is limited by the ParA family of partitioning systems. Mol. Microbiol. 67(5):935-946.
Larsen, R.A., Cusumano, C., Fujioka, A., Lim-Fong, G., Patterson, P., and Pogliano, J. 2007. Treadmilling of a prokaryotic tubulin-like protein, TubZ, required for plasmid stability in Bacillus thuringiensis. Genes Dev. 21(11):1340-1352.
Lim, G.E., Derman, A.I., and Pogliano, J. 2005. Bacterial DNA segregation by dynamic SopA polymers. Proc. Natl. Acad. Sci. USA 102(49):17658-17663.
Pogliano, J. 2008. The bacterial cytoskeleton. Curr. Opin. Cell. Biol. 20(1):19-27.
