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Legionella pneumophila proteins that regulate Rab1 membrane cycling


Rab1 is a GTPase that regulates the transport of endoplasmic-reticulum-derived vesicles in eukaryotic cells. The intracellular pathogen Legionella pneumophila subverts Rab1 function to create a vacuole that supports bacterial replication by a mechanism that is not well understood. Here we describe L. pneumophila proteins that control Rab1 activity directly. We show that a region in the DrrA (defect in Rab1 recruitment A) protein required for recruitment of Rab1 to membranes functions as a guanine nucleotide dissociation inhibitor displacement factor. A second region of the DrrA protein stimulated Rab1 activation by functioning as a guanine nucleotide exchange factor. The LepB protein was found to inactivate Rab1 by stimulating GTP hydrolysis, indicating that LepB has GTPase-activating protein activity that regulates removal of Rab proteins from membranes. Thus, L. pneumophila encodes proteins that regulate three distinct biochemical reactions critical for Rab GTPase membrane cycling to redirect Rab1 to the pathogen-occupied vacuole and to control Rab1 function.

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Figure 1: DrrA has GDF activity that is required for activation of Rab1 bound to Rab GDI.
Figure 2: LepB interacts with GTP-bound Rab1 and is detected on the early LCV.
Figure 3: LepB interacts with Rab1–GTP and disrupts secretory transport in mammalian cells.
Figure 4: LepB is a Rab1-specific GAP.


  1. 1

    Zerial, M. & McBride, H. Rab proteins as membrane organizers. Nature Rev. Mol. Cell Biol. 2, 107–117 (2001)

    CAS  Article  Google Scholar 

  2. 2

    Rink, J., Ghigo, E., Kalaidzidis, Y. & Zerial, M. Rab conversion as a mechanism of progression from early to late endosomes. Cell 122, 735–749 (2005)

    CAS  Article  Google Scholar 

  3. 3

    Sasaki, T. et al. Purification and characterization from bovine brain cytosol of a protein that inhibits the dissociation of GDP from and the subsequent binding of GTP to smg p25A, a ras p21-like GTP-binding protein. J. Biol. Chem. 265, 2333–2337 (1990)

    CAS  Google Scholar 

  4. 4

    Araki, S., Kikuchi, A., Hata, Y., Isomura, M. & Takai, Y. Regulation of reversible binding of smg p25A, a ras p21-like GTP-binding protein, to synaptic plasma membranes and vesicles by its specific regulatory protein, GDP dissociation inhibitor. J. Biol. Chem. 265, 13007–13015 (1990)

    CAS  Google Scholar 

  5. 5

    Ullrich, O. et al. Rab GDP dissociation inhibitor as a general regulator for the membrane association of rab proteins. J. Biol. Chem. 268, 18143–18150 (1993)

    CAS  Google Scholar 

  6. 6

    Dirac-Svejstrup, A. B., Sumizawa, T. & Pfeffer, S. R. Identification of a GDI displacement factor that releases endosomal Rab GTPases from Rab-GDI. EMBO J. 16, 465–472 (1997)

    CAS  Article  Google Scholar 

  7. 7

    Markgraf, D. F., Peplowska, K. & Ungermann, C. Rab cascades and tethering factors in the endomembrane system. FEBS Lett. 581, 2125–2130 (2007)

    CAS  Article  Google Scholar 

  8. 8

    Grosshans, B. L., Ortiz, D. & Novick, P. Rabs and their effectors: achieving specificity in membrane traffic. Proc. Natl Acad. Sci. USA 103, 11821–11827 (2006)

    ADS  CAS  Article  Google Scholar 

  9. 9

    Strom, M., Vollmer, P., Tan, T. J. & Gallwitz, D. A yeast GTPase-activating protein that interacts specifically with a member of the Ypt/Rab family. Nature 361, 736–739 (1993)

    ADS  CAS  Article  Google Scholar 

  10. 10

    Albert, S., Will, E. & Gallwitz, D. Identification of the catalytic domains and their functionally critical arginine residues of two yeast GTPase-activating proteins specific for Ypt/Rab transport GTPases. EMBO J. 18, 5216–5225 (1999)

    CAS  Article  Google Scholar 

  11. 11

    Horwitz, M. A. Formation of a novel phagosome by the Legionnaires’ disease bacterium (Legionella pneumophila) in human monocytes. J. Exp. Med. 158, 1319–1331 (1983)

    CAS  Article  Google Scholar 

  12. 12

    Swanson, M. S. & Isberg, R. R. Association of Legionella pneumophila with the macrophage endoplasmic reticulum. Infect. Immun. 63, 3609–3620 (1995)

    CAS  Google Scholar 

  13. 13

    Kagan, J. C. & Roy, C. R. Legionella phagosomes intercept vesicular traffic from endoplasmic reticulum exit sites. Nature Cell Biol. 4, 945–954 (2002)

    CAS  Article  Google Scholar 

  14. 14

    Kagan, J. C., Stein, M. P., Pypaert, M. & Roy, C. R. Legionella subvert the functions of Rab1 and Sec22b to create a replicative organelle. J. Exp. Med. 199, 1201–1211 (2004)

    CAS  Article  Google Scholar 

  15. 15

    Derre, I. & Isberg, R. R. Legionella pneumophila replication vacuole formation involves rapid recruitment of proteins of the early secretory system. Infect. Immun. 72, 3048–3053 (2004)

    CAS  Article  Google Scholar 

  16. 16

    Segal, G., Purcell, M. & Shuman, H. A. Host cell killing and bacterial conjugation require overlapping sets of genes within a 22-kb region of the Legionella pneumophila genome. Proc. Natl Acad. Sci. USA 95, 1669–1674 (1998)

    ADS  CAS  Article  Google Scholar 

  17. 17

    Vogel, J. P., Andrews, H. L., Wong, S. K. & Isberg, R. R. Conjugative transfer by the virulence system of Legionella pneumophila . Science 279, 873–876 (1998)

    ADS  CAS  Article  Google Scholar 

  18. 18

    Nagai, H., Kagan, J. C., Zhu, X., Kahn, R. A. & Roy, C. R. A bacterial guanine nucleotide exchange factor activates ARF on Legionella phagosomes. Science 295, 679–682 (2002)

    ADS  CAS  Article  Google Scholar 

  19. 19

    Murata, T. et al. The Legionella pneumophila effector protein DrrA is a Rab1 guanine nucleotide-exchange factor. Nature Cell Biol. 8, 971–977 (2006)

    CAS  Article  Google Scholar 

  20. 20

    Machner, M. P. & Isberg, R. R. Targeting of host Rab GTPase function by the intravacuolar pathogen Legionella pneumophila . Dev. Cell 11, 47–56 (2006)

    CAS  Article  Google Scholar 

  21. 21

    Sivars, U., Aivazian, D. & Pfeffer, S. R. Yip3 catalyses the dissociation of endosomal Rab-GDI complexes. Nature 425, 856–859 (2003)

    ADS  CAS  Article  Google Scholar 

  22. 22

    Stroupe, C. & Brunger, A. T. Crystal structures of a Rab protein in its inactive and active conformations. J. Mol. Biol. 304, 585–598 (2000)

    CAS  Article  Google Scholar 

  23. 23

    Pylypenko, O. et al. Structure of doubly prenylated Ypt1:GDI complex and the mechanism of GDI-mediated Rab recycling. EMBO J. 25, 13–23 (2006)

    CAS  Article  Google Scholar 

  24. 24

    Chen, J. et al. Legionella effectors that promote nonlytic release from protozoa. Science 303, 1358–1361 (2004)

    ADS  CAS  Article  Google Scholar 

  25. 25

    Pan, X., Eathiraj, S., Munson, M. & Lambright, D. G. TBC-domain GAPs for Rab GTPases accelerate GTP hydrolysis by a dual-finger mechanism. Nature 442, 303–306 (2006)

    ADS  CAS  Article  Google Scholar 

  26. 26

    Geng, J., Shin, M. E., Gilbert, P. M., Collins, R. N. & Burd, C. G. Saccharomyces cerevisiae Rab-GDI displacement factor ortholog Yip3p forms distinct complexes with the Ypt1 Rab GTPase and the reticulon Rtn1p. Eukaryot. Cell 4, 1166–1174 (2005)

    CAS  Article  Google Scholar 

  27. 27

    Robinson, C. G. & Roy, C. R. Attachment and fusion of endoplasmic reticulum with vacuoles containing Legionella pneumophila . Cell. Microbiol. 8, 793–805 (2006)

    CAS  Article  Google Scholar 

  28. 28

    Satoh, A., Wang, Y., Malsam, J., Beard, M. B. & Warren, G. Golgin-84 is a rab1 binding partner involved in Golgi structure. Traffic 4, 153–161 (2003)

    CAS  Article  Google Scholar 

  29. 29

    Christoforidis, S. & Zerial, M. Purification and identification of novel Rab effectors using affinity chromatography. Methods 20, 403–410 (2000)

    CAS  Article  Google Scholar 

  30. 30

    Amor, J. C. et al. The structure of RalF, an ADP-ribosylation factor guanine nucleotide exchange factor from Legionella pneumophila, reveals the presence of a cap over the active site. J. Biol. Chem. 280, 1392–1400 (2005)

    CAS  Article  Google Scholar 

  31. 31

    Kagan, J. C., Murata, T. & Roy, C. R. Analysis of Rab1 recruitment to vacuoles containing Legionella pneumophila . Methods Enzymol. 403, 71–81 (2005)

    CAS  Article  Google Scholar 

  32. 32

    Celada, A., Gray, P. W., Rinderknecht, E. & Schreiber, R. D. Evidence for a gamma-interferon receptor that regulates macrophage tumoricidal activity. J. Exp. Med. 160, 55–74 (1984)

    CAS  Article  Google Scholar 

  33. 33

    Merriam, J. J., Mathur, R., Maxfield-Boumil, R. & Isberg, R. R. Analysis of the Legionella pneumophila fliI gene: intracellular growth of a defined mutant defective for flagellum biosynthesis. Infect. Immun. 65, 2497–2501 (1997)

    CAS  Google Scholar 

  34. 34

    Campodonico, E. M., Chesnel, L. & Roy, C. R. A yeast genetic system for the identification and characterization of substrate proteins transferred into host cells by the Legionella pneumophila Dot/Icm system. Mol. Microbiol. 56, 918–933 (2005)

    CAS  Article  Google Scholar 

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We thank G. Warren for his advice on the Rab1 binding studies, and M. P. Stein and L. Chesnel for technical suggestions and advice. This work was supported by the NIH (C.R.R. and D.G.L.) and an NSF Graduate Research Fellowship (A.I.).

Author Contributions C.R.R. supervised the project. A.I. conducted all of the experiments in this study with the exception of the GEF assays, which were conducted by A.D. D.G.L. assisted with the GAP assays. All authors contributed to the writing of the manuscript

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Correspondence to Craig R. Roy.

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The authors declare no competing financial interests.

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Ingmundson, A., Delprato, A., Lambright, D. et al. Legionella pneumophila proteins that regulate Rab1 membrane cycling. Nature 450, 365–369 (2007).

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