Stability, structural and functional properties of a monomeric, calcium-loaded adenylate cyclase toxin, CyaA, from Bordetella pertussis.

Abstract : Bordetella pertussis, the causative agent of whooping cough, secretes an adenylate cyclase toxin, CyaA, which invades eukaryotic cells and alters their physiology by cAMP overproduction. Calcium is an essential cofactor of CyaA, as it is the case for most members of the Repeat-in-ToXins (RTX) family. We show that the calcium-bound, monomeric form of CyaA, hCyaAm, conserves its permeabilization and haemolytic activities, even in a fully calcium-free environment. In contrast, hCyaAm requires sub-millimolar calcium in solution for cell invasion, indicating that free calcium in solution is involved in the CyaA toxin translocation process. We further report the first in solution structural characterization of hCyaAm, as deduced from SAXS, mass spectrometry and hydrodynamic studies. We show that hCyaAm adopts a compact and stable state that can transiently conserve its conformation even in a fully calcium-free environment. Our results therefore suggest that in hCyaAm, the C-terminal RTX-domain is stabilized in a high-affinity calcium-binding state by the N-terminal domains while, conversely, calcium binding to the C-terminal RTX-domain strongly stabilizes the N-terminal regions. Hence, the different regions of hCyaAm appear tightly connected, leading to stabilization effects between domains. The hysteretic behaviour of CyaA in response to calcium is likely shared by other RTX cytolysins.
Type de document :
Article dans une revue
Scientific Reports, Nature Publishing Group, 2017, 7, pp.42065. 〈10.1038/srep42065〉
Liste complète des métadonnées

Littérature citée [78 références]  Voir  Masquer  Télécharger

https://hal-pasteur.archives-ouvertes.fr/pasteur-01508525
Contributeur : Bénédicte Benedic <>
Soumis le : vendredi 14 avril 2017 - 11:59:09
Dernière modification le : vendredi 8 juin 2018 - 08:51:52

Fichier

Cannella S_2017.pdf
Publication financée par une institution

Licence


Distributed under a Creative Commons Paternité 4.0 International License

Identifiants

Citation

Sara E Cannella, Véronique Yvette Ntsogo Enguéné, Marilyne Davi, Christian Malosse, Ana Cristina Sotomayor Pérez, et al.. Stability, structural and functional properties of a monomeric, calcium-loaded adenylate cyclase toxin, CyaA, from Bordetella pertussis.. Scientific Reports, Nature Publishing Group, 2017, 7, pp.42065. 〈10.1038/srep42065〉. 〈pasteur-01508525〉

Partager

Métriques

Consultations de la notice

261

Téléchargements de fichiers

135