Abstract
Internalisation of the pathogenic bacterium Listeria monocytogenes involves interactions between the invasion protein InlB and the hepatocyte growth factor receptor, Met. Using colocalisation studies, dominant-negative constructs and small interfering RNA (siRNA), we demonstrate a cell-type-dependent requirement for various WASP-related proteins in Listeria entry and InlB-induced membrane ruffling. The WAVE2 isoform is essential for InlB-induced cytoskeletal rearrangements in Vero cells. In HeLa cells, WAVE1, WAVE2 and N-WASP cooperate to promote these processes. Abi1, a key component of WAVE complexes, is recruited at the entry site in both cell types and its inactivation by RNA interference impairs InlB-mediated processes. Ena/VASP proteins also play a role in Listeria internalization, and their deregulation by sequestration or overexpression, modifies actin cups beneath entering particles. Taken together, these results identify the WAVE complex, N-WASP and Ena/VASP as key effectors of the Met signalling pathway and of Listeria entry and highlight the existence of redundant and/or cooperative functions among WASP-family members.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Adaptor Proteins, Signal Transducing / genetics
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Adaptor Proteins, Signal Transducing / metabolism*
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Animals
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism*
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Cell Membrane / metabolism
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Chlorocebus aethiops
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Cytoskeletal Proteins
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism*
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HeLa Cells
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Humans
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Listeria monocytogenes / genetics
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Listeria monocytogenes / physiology*
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Membrane Proteins / metabolism
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Microfilament Proteins / antagonists & inhibitors
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Microfilament Proteins / genetics
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Microfilament Proteins / metabolism
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Nerve Tissue Proteins / antagonists & inhibitors
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Nerve Tissue Proteins / genetics
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Nerve Tissue Proteins / metabolism*
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Phagocytosis / physiology
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Proto-Oncogene Proteins c-met / metabolism*
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RNA, Small Interfering / pharmacology
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Signal Transduction / physiology
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Vero Cells
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Wiskott-Aldrich Syndrome Protein Family
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Wiskott-Aldrich Syndrome Protein, Neuronal
Substances
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ABI1 protein, human
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Adaptor Proteins, Signal Transducing
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Bacterial Proteins
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Cytoskeletal Proteins
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DNA-Binding Proteins
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ENA-VASP proteins
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Membrane Proteins
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Microfilament Proteins
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Nerve Tissue Proteins
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RNA, Small Interfering
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WASL protein, human
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Wiskott-Aldrich Syndrome Protein Family
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Wiskott-Aldrich Syndrome Protein, Neuronal
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inlB protein, Listeria monocytogenes
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Proto-Oncogene Proteins c-met