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Role of lipid rafts in E-cadherin-- and HGF-R/Met--mediated entry of Listeria monocytogenes into host cells.

Seveau S, Bierne H, Giroux S, Prévost MC, Cossart P - J. Cell Biol. (2004)

Bottom Line: We analyzed which molecular events require membrane cholesterol and found that the presence of E-cadherin in lipid domains was necessary for initial interaction with internalin to promote bacterial entry.In contrast, the initial interaction of InlB with HGF-R did not require membrane cholesterol, whereas downstream signaling leading to F-actin polymerization was cholesterol dependent.Our work, in addition to documenting for the first time the role of lipid rafts in Listeria entry, provides the first evidence that E-cadherin and HGF-R require lipid domain integrity for their full activity.

View Article: PubMed Central - PubMed

Affiliation: Unité des Interactions Bactéries-Cellules, INSERM U604, Institut Pasteur, 75015 Paris Cedex 15, France.

ABSTRACT
Listeria monocytogenes uptake by nonphagocytic cells is promoted by the bacterial invasion proteins internalin and InlB, which bind to their host receptors E-cadherin and hepatocyte growth factor receptor (HGF-R)/Met, respectively. Here, we present evidence that plasma membrane organization in lipid domains is critical for Listeria uptake. Cholesterol depletion by methyl-beta-cyclodextrin reversibly inhibited Listeria entry. Lipid raft markers, such as glycosylphosphatidylinositol-linked proteins, a myristoylated and palmitoylated peptide and the ganglioside GM1 were recruited at the bacterial entry site. We analyzed which molecular events require membrane cholesterol and found that the presence of E-cadherin in lipid domains was necessary for initial interaction with internalin to promote bacterial entry. In contrast, the initial interaction of InlB with HGF-R did not require membrane cholesterol, whereas downstream signaling leading to F-actin polymerization was cholesterol dependent. Our work, in addition to documenting for the first time the role of lipid rafts in Listeria entry, provides the first evidence that E-cadherin and HGF-R require lipid domain integrity for their full activity.

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Cholesterol depletion abrogates partially the formation of actin-rich membrane ruffles. Control and cholesterol-depleted Vero cells were stimulated or not (NS) for 2 min with soluble InlB or HGF. Cells were then fixed and labeled for F-actin (Alexa Fluor 488 phalloidin). Phase contrast and fluorescent images were acquired with a 40× objective. Bar, 10 μm.
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fig10: Cholesterol depletion abrogates partially the formation of actin-rich membrane ruffles. Control and cholesterol-depleted Vero cells were stimulated or not (NS) for 2 min with soluble InlB or HGF. Cells were then fixed and labeled for F-actin (Alexa Fluor 488 phalloidin). Phase contrast and fluorescent images were acquired with a 40× objective. Bar, 10 μm.

Mentions: We then analyzed if cholesterol depletion could affect the formation of actin-rich phagocytic cups at the entry site. As shown in Fig. 8 A, in contrast to control cells, after cholesterol depletion F-actin cups were rarely visualized around the InlB-coated beads which recruited HGF-R. Furthermore, cholesterol depletion partially impaired the formation of F-actin-rich membrane ruffles normally induced by soluble InlB (8 nM) or HGF (0.6 nM; Fig. 10).


Role of lipid rafts in E-cadherin-- and HGF-R/Met--mediated entry of Listeria monocytogenes into host cells.

Seveau S, Bierne H, Giroux S, Prévost MC, Cossart P - J. Cell Biol. (2004)

Cholesterol depletion abrogates partially the formation of actin-rich membrane ruffles. Control and cholesterol-depleted Vero cells were stimulated or not (NS) for 2 min with soluble InlB or HGF. Cells were then fixed and labeled for F-actin (Alexa Fluor 488 phalloidin). Phase contrast and fluorescent images were acquired with a 40× objective. Bar, 10 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2172418&req=5

fig10: Cholesterol depletion abrogates partially the formation of actin-rich membrane ruffles. Control and cholesterol-depleted Vero cells were stimulated or not (NS) for 2 min with soluble InlB or HGF. Cells were then fixed and labeled for F-actin (Alexa Fluor 488 phalloidin). Phase contrast and fluorescent images were acquired with a 40× objective. Bar, 10 μm.
Mentions: We then analyzed if cholesterol depletion could affect the formation of actin-rich phagocytic cups at the entry site. As shown in Fig. 8 A, in contrast to control cells, after cholesterol depletion F-actin cups were rarely visualized around the InlB-coated beads which recruited HGF-R. Furthermore, cholesterol depletion partially impaired the formation of F-actin-rich membrane ruffles normally induced by soluble InlB (8 nM) or HGF (0.6 nM; Fig. 10).

Bottom Line: We analyzed which molecular events require membrane cholesterol and found that the presence of E-cadherin in lipid domains was necessary for initial interaction with internalin to promote bacterial entry.In contrast, the initial interaction of InlB with HGF-R did not require membrane cholesterol, whereas downstream signaling leading to F-actin polymerization was cholesterol dependent.Our work, in addition to documenting for the first time the role of lipid rafts in Listeria entry, provides the first evidence that E-cadherin and HGF-R require lipid domain integrity for their full activity.

View Article: PubMed Central - PubMed

Affiliation: Unité des Interactions Bactéries-Cellules, INSERM U604, Institut Pasteur, 75015 Paris Cedex 15, France.

ABSTRACT
Listeria monocytogenes uptake by nonphagocytic cells is promoted by the bacterial invasion proteins internalin and InlB, which bind to their host receptors E-cadherin and hepatocyte growth factor receptor (HGF-R)/Met, respectively. Here, we present evidence that plasma membrane organization in lipid domains is critical for Listeria uptake. Cholesterol depletion by methyl-beta-cyclodextrin reversibly inhibited Listeria entry. Lipid raft markers, such as glycosylphosphatidylinositol-linked proteins, a myristoylated and palmitoylated peptide and the ganglioside GM1 were recruited at the bacterial entry site. We analyzed which molecular events require membrane cholesterol and found that the presence of E-cadherin in lipid domains was necessary for initial interaction with internalin to promote bacterial entry. In contrast, the initial interaction of InlB with HGF-R did not require membrane cholesterol, whereas downstream signaling leading to F-actin polymerization was cholesterol dependent. Our work, in addition to documenting for the first time the role of lipid rafts in Listeria entry, provides the first evidence that E-cadherin and HGF-R require lipid domain integrity for their full activity.

Show MeSH
Related in: MedlinePlus