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Structural mimicry for vinculin activation by IpaA, a virulence factor of Shigella flexneri
Author(s) -
Hamiaux Cyril,
van Eerde André,
Parsot Claude,
Broos Jaap,
Dijkstra Bauke W
Publication year - 2006
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.1038/sj.embor.7400753
Subject(s) - vinculin , shigella flexneri , internalization , microbiology and biotechnology , cytoskeleton , biology , actin , effector , virulence factor , secretion , virulence , cell , biochemistry , escherichia coli , gene
Invasion of epithelial cells by Shigella flexneri is characterized by cytoskeletal rearrangements of the host cell membrane, promoting internalization of the bacterium. The bacterial effector IpaA is injected into the epithelial cell by a type III secretion apparatus and recruits vinculin to regulate actin polymerization at the site of entry. We analysed the complex formed between a carboxy‐terminal fragment of IpaA (IpaA 560−633 ) and the vinculin D1 domain (VD1), both in crystals and in solution. We present evidence that IpaA 560−633 has two α‐helical vinculin‐binding sites that simultaneously bind two VD1 molecules. The interaction of IpaA 560−633 with VD1 is highly similar to the interaction of the endogenous, eukaryotic proteins talin and α‐actinin with VD1, showing that Shigella uses a structural mimicry strategy to activate vinculin.