Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.
Submitted on August 13, 2007
Accepted on October 9, 2007
A Bifunctional Bacterial Protein Links GDI Displacement to Rab1 Activation
Matthias P. Machner 1 and Ralph R. Isberg 2*
1 Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA. 2 Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA.; Howard Hughes Medical Institute, Tufts University School of Medicine, Boston, MA 02111, USA.
* To whom correspondence should be addressed.
Ralph R. Isberg , E-mail: ralph.isberg{at}tufts.edu
Rab guanosine triphosphatases (GTPases) regulate vesicle traffickingin eukaryotic cells by reversibly associating with lipid membranes.Inactive Rab GTPases are maintained in the cytosol by bindingto GDP dissociation inhibitor (GDI). It is believed that specializedproteins are required to displace GDI from Rab GTPases beforeRab activation by GDP-GTP exchange factors (GEFs). Here we foundthat SidM from Legionella pneumophila could act as both GEFand GDI displacement factor (GDF) for Rab1. Rab1 released fromGDI was inserted into liposomal membranes and was used as asubstrate for SidM-mediated nucleotide exchange. During hostcell infection, recruitment of Rab1 to Legionella-containingvacuolesdepended on the GDF activity of SidM. Thus, GDF andGEF activity can be promoted by a single protein, and GDF activitycan coordinate Rab1 recruitment from the GDI-bound pool.
The editors suggest the following Related Resources on Science sites:
In Science Signaling
EDITORS' CHOICE
Stella M. Hurtley (13 November 2007) Sci. STKE2007 (412), tw419.
[DOI: 10.1126/stke.4122007tw419] |Abstract »
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Actin Dynamics and Rho GTPases Regulate the Size and Formation of Parasitophorous Vacuoles Containing Coxiella burnetii.
M. Aguilera, R. Salinas, E. Rosales, S. Carminati, M. I. Colombo, and W. Beron (2009)
Infect. Immun.
77, 4609-4620
|Abstract »|Full Text »|PDF »
New Insights into How the Rho Guanine Nucleotide Dissociation Inhibitor Regulates the Interaction of Cdc42 with Membranes.
J. L. Johnson, J. W. Erickson, and R. A. Cerione (2009)
J. Biol. Chem.
284, 23860-23871
|Abstract »|Full Text »|PDF »
{sigma}S Controls Multiple Pathways Associated with Intracellular Multiplication of Legionella pneumophila.
G. Hovel-Miner, S. Pampou, S. P. Faucher, M. Clarke, I. Morozova, P. Morozov, J. J. Russo, H. A. Shuman, and S. Kalachikov (2009)
J. Bacteriol.
191, 2461-2473
|Abstract »|Full Text »|PDF »
Rab1 Guanine Nucleotide Exchange Factor SidM Is a Major Phosphatidylinositol 4-Phosphate-binding Effector Protein of Legionella pneumophila.
E. Brombacher, S. Urwyler, C. Ragaz, S. S. Weber, K. Kami, M. Overduin, and H. Hilbi (2009)
J. Biol. Chem.
284, 4846-4856
|Abstract »|Full Text »|PDF »
Identification of a Hypervariable Region Containing New Legionella pneumophila Icm/Dot Translocated Substrates by Using the Conserved icmQ Regulatory Signature.
Significant Role for ladC in Initiation of Legionella pneumophila Infection.
H. J. Newton, F. M. Sansom, J. Dao, C. Cazalet, H. Bruggemann, C. Albert-Weissenberger, C. Buchrieser, N. P. Cianciotto, and E. L. Hartland (2008)
Infect. Immun.
76, 3075-3085
|Abstract »|Full Text »|PDF »
Enzymatic Properties of an Ecto-nucleoside Triphosphate Diphosphohydrolase from Legionella pneumophila: SUBSTRATE SPECIFICITY AND REQUIREMENT FOR VIRULENCE.
F. M. Sansom, P. Riedmaier, H. J. Newton, M. A. Dunstone, C. E. Muller, H. Stephan, E. Byres, T. Beddoe, J. Rossjohn, P. J. Cowan, et al. (2008)
J. Biol. Chem.
283, 12909-12918
|Abstract »|Full Text »|PDF »
