Shigella IpaA Binding to Talin Stimulates Filopodial Capture and Cell Adhesion.
Valencia-Gallardo, C., Bou-Nader, C., Aguilar-Salvador, D.I., Carayol, N., Quenech'Du, N., Pecqueur, L., Park, H., Fontecave, M., Izard, T., Tran Van Nhieu, G.(2019) Cell Rep 26: 921-932.e6
- PubMed: 30673614 
- DOI: https://doi.org/10.1016/j.celrep.2018.12.091
- Primary Citation of Related Structures:  
5NL1 - PubMed Abstract: 
The Shigella type III effector IpaA contains three binding sites for the focal adhesion protein vinculin (VBSs), which are involved in bacterial invasion of host cells. Here, we report that IpaA VBS3 unexpectedly binds to talin. The 2.5 Å resolution crystal structure of IpaA VBS3 in complex with the talin H1-H4 helices shows a tightly folded α-helical bundle, which is in contrast to the bundle unraveling upon vinculin interaction. High-affinity binding to talin H1-H4 requires a core of hydrophobic residues and electrostatic interactions conserved in talin VBS H46. Remarkably, IpaA VBS3 localizes to filopodial distal adhesions enriched in talin, but not vinculin. In addition, IpaA VBS3 binding to talin was required for filopodial adhesions and efficient capture of Shigella. These results point to the functional diversity of VBSs and support a specific role for talin binding by a subset of VBSs in the formation of filopodial adhesions.
Organizational Affiliation: 
Equipe Communication Intercellulaire et Infections Microbiennes, Centre de Recherche Interdisciplinaire en Biologie (CIRB), Collège de France, 75005 Paris, France; INSERM U1050, 75005 Paris, France; Centre National de la Recherche Scientifique UMR7241, 75005 Paris, France; MEMOLIFE Laboratory of Excellence and Paris Science Lettres, 75005 Paris, France.