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Protein delivery into eukaryotic cells by type III secretion machines

Naturevolume 444pages567573 (2006) | Download Citation



Bacteria that have sustained long-standing close associations with eukaryotic hosts have evolved specific adaptations to survive and replicate in this environment. Perhaps one of the most remarkable of those adaptations is the type III secretion system (T3SS)—a bacterial organelle that has specifically evolved to deliver bacterial proteins into eukaryotic cells. Although originally identified in a handful of pathogenic bacteria, T3SSs are encoded by a large number of bacterial species that are symbiotic or pathogenic for humans, other animals including insects or nematodes, and plants. The study of these systems is leading to unique insights into not only organelle assembly and protein secretion but also mechanisms of symbiosis and pathogenesis.

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We thank T. Marlovits and E. Stebbins for generously providing the images presented in Fig. 1 and 4, and members of the Galán laboratory for critical review of the manuscript. Work in the laboratory of J. G. is supported by the NIH.

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  1. Section of Microbial Pathogenesis, Yale University School of Medicine, Boyer Center for Molecular Medicine, New Haven, Connecticut, 0636, USA

    • Jorge E. Galán
  2. Department of Molecular Biology, Umea University, Umea, SE-901 87, Sweden

    • Hans Wolf-Watz


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Correspondence to Jorge E. Galán.

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