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Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes
Published on: September 19, 2013
Characterization of a Listeria monocytogenes protein interfering with Rab5a.
Carmen Alvarez-Dominguez1, Fidel Madrazo-Toca, Lorena Fernandez-Prieto
1Servicio de Inmunología and Instituto de Formación e Investigación Marqués de Valdecilla (IFIMAV), Hospital Universitario "Marqués de Valdecilla", 39008 Santander, Spain. calvarez@humv.es
Traffic (Copenhagen, Denmark)
|December 20, 2007
Summary
Listeria monocytogenes uses its GAPDH protein to target Rab5a, inhibiting phagosome-endosome fusion. This novel virulence factor disrupts essential cellular processes for bacterial survival.
Area of Science:
- Microbiology
- Cell Biology
- Biochemistry
Background:
- Listeria monocytogenes (LM) employs a phagocytic strategy involving Rab5a recruitment and inhibition.
- Rab5a plays a crucial role in phagosome maturation and endosome fusion.
Purpose of the Study:
- To identify the Listeria protein responsible for Rab5a recruitment and inhibition.
- To elucidate the mechanism by which this protein disrupts Rab5a function.
Main Methods:
- Identification of a Listeria protein binding to Rab5a.
- Analysis of the protein's sequence and enzymatic domains.
- Examination of ADP-ribosylating activity and its effect on Rab5a interactions.
Main Results:
- A Listeria glyceraldehyde-3-phosphate dehydrogenase (GAPDH, p40 protein) was identified as the Rab5a-binding protein.
- Listeria GAPDH exhibits ADP-ribosylating activity, specifically targeting Rab5a.
- This activity inhibits Rab5a-exchange factor (Vps9) and GDI interaction, blocking phagosome-endosome fusion.
Conclusions:
- Listeria GAPDH is a novel virulence factor that targets Rab5a through ADP-ribosylation.
- This mechanism impairs Rab5a-mediated phagosome-endosome fusion, aiding bacterial survival.
- This represents a unique strategy among intracellular gram-positive pathogens.
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