Title

The bacterial virulence factor InlC perturbs apical cell junctions and promotes cell-to-cell spread of Listeria

Authors

Authors

T. Rajabian; B. Gavicherla; M. Heisig; S. Muller-Altrock; W. Goebel; S. D. Gray-Owen;K. Ireton

Abbreviated Journal Title

Nat. Cell Biol.

Keywords

ACTIN-BASED MOTILITY; LEUCINE-RICH REPEAT; MONOCYTOGENES; PROTEINS; DOMAINS; FAMILY; TUBA; PATHOGENESIS; CYTOSKELETON; INTERNALINS; Cell Biology

Abstract

Several pathogenic bacteria, including Listeria monocytogenes, use an F-actin motility process to spread between mammalian cells1. Actin 'comet tails' propel Listeria through the cytoplasm, resulting in bacteria-containing membrane protrusions that are internalized by neighbouring cells. The mechanism by which Listeria overcomes cortical tension to generate protrusions is unknown. Here, we identify bacterial and host proteins that directly regulate protrusions. We show that efficient spreading between polarized epithelial cells requires the secreted Listeria virulence protein InlC (internalin C). We next identify the mammalian adaptor protein Tuba as a ligand of InlC. InlC binds to a carboxy-terminal SH3 domain in Tuba, which normally engages the human actin regulatory protein N-WASP(2). InlC promotes protrusion formation by inhibiting Tuba and N-WASP activity, probably by impairing binding of N-WASP to the Tuba SH3 domain. Tuba and N-WASP are known to control the structure of apical junctions in epithelial cells(3). We demonstrate that, by inhibiting Tuba and N-WASP, InlC makes taut apical junctions become slack. Experiments with myosin II inhibitors indicate that InlC-mediated perturbation of apical junctions accounts for the role of this bacterial protein in protrusion formation. Collectively, our results suggest that InlC promotes bacterial dissemination by relieving cortical tension, thereby enhancing the ability of motile bacteria to deform the plasma membrane into protrusions.

Journal Title

Nature Cell Biology

Volume

11

Issue/Number

10

Publication Date

1-1-2009

Document Type

Article

Language

English

First Page

1212

Last Page

U104

WOS Identifier

WOS:000270382000010

ISSN

1465-7392

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