Cell Microbiol. 2010 Apr 1; 12(4):530-44
All selected articles haveThis article has been added to your saved articles
You can follow/unfollow articles via MyF1000 or via the article or browse pages.
In this study, the authors propose galectin-3, a beta-galactoside binding protein, as a novel and potentially universal tool to visualise and quantitate the lysis of microbe-containing vacuoles in macrophages or other model host cell systems. This experimental strategy will be helpful to improve our understanding of the mechanisms underlying vacuole rupture.
The main finding is that galectin-3, a macrophage cytosolic lectin, is recruited on membranes of vacuoles containing the Gram-negative pathogen Shigella. This phenomenon is concomitant with the lysis of these compartments. Thus, galectin-3 represents a potential marker of vacuole lysis by bacteria. Galectin-3 belongs to the galectins, a family of proteins with a binding site for beta-galactosides. Two other studies reported its recruitment on the membrane of Shigella-containing vacuoles but little was known about how and why this occurred {1,2}. In this article, the authors discovered that the protein interacts with host glycoconjugates that become exposed on the surface of Shigella-containing vacuoles during rupture. This recruitment occurs specifically during the lysis of the compartments by Shigella and also by Listeria -- Gram-negative and Gram-positive bacteria, respectively. Thus, galectin-3 could be used as a novel and potentially universal marker to spot vacuole lysis by bacteria. The observed accumulation of galectin-3 on vacuole membranes also depends on bacterial factors, but their identity and mechanism of action have not yet been ascertained.
Soldati T and Arafah S: F1000Prime Recommendation of [Paz I et al., Cell Microbiol 2010, 12(4):530-44]. In F1000Prime, 05 May 2010; DOI: 10.3410/f.3068961.2751061. F1000Prime.com/3068961#eval2751061
F1000Prime Recommendations, Dissents and Comments for [Paz I et al., Cell Microbiol 2010, 12(4):530-44]. In F1000Prime, 18 Jun 2013; F1000Prime.com/3068961
No comments yet.
Shigella bacteria invade macrophages and epithelial cells and following internalization lyse the phagosome and escape to the cytoplasm. Galectin-3, an abundant protein in macrophages and epithelial cells, belongs to a family of beta-galactoside-binding proteins, the galectins, with many proposed functions in immune response, development, differentiation, cancer and infection. Galectins are synthesized as cytosolic proteins and following non-classical secretion bind extracellular beta-galactosides. Here we analysed the localization of galectin-3 following entry of Shigella into the cytosol and detected a striking phenomenon. Very shortly after bacterial invasion, intracellular galectin-3 accumulated in structures in vicinity to internalized bacteria. By using immuno-electron microscopy analysis we identified galectin-3 in membranes localized in the phagosome and in tubules and vesicles that derive from the endocytic pathway. We also demonstrated that the binding of galectin-3 to host N-acetyllactosamine-containing glycans, was required for forming the structures. Accumulation of the structures was a type three secretion system-dependent process. More specifically, existence of structures was strictly dependent upon lysis of the phagocytic vacuole and could be shown also by Gram-positive Listeria and Salmonella sifA mutant. We suggest that galectin-3-containing structures may serve as a potential novel tool to spot vacuole lysis.
DOI: 10.1111/j.1462-5822.2009.01415.x
PMID: 19951367
has been added to your "Faculty I'm Following" page in MyF1000
Follow/Unfollow any Faculty via their recommendations, biography pages, or MyF1000
