Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Bordetella pertussis, the pathogenic bacteria responsible for whooping cough, secretes several virulence factors, among which is the adenylate cyclase toxin (CyaA) that plays a crucial role in the early stages of human respiratory tract colonization. CyaA invades target cells by translocating its catalytic domain directly across the plasma membrane and overproduces cAMP, leading to cell death. The molecular process leading to the translocation of the catalytic domain remains largely unknown. We have previously shown that the catalytic domain per se, AC384, encompassing residues 1-384 of CyaA, did not interact with lipid bilayer, whereas a longer polypeptide, AC489, spanning residues 1-489, binds to membranes and permeabilizes vesicles. Moreover, deletion of residues 375-485 within CyaA abrogated the translocation of the catalytic domain into target cells. Here, we further identified within this region a peptidic segment that exhibits membrane interaction properties. A synthetic peptide, P454, corresponding to this sequence (residues 454-485 of CyaA) was characterized by various biophysical approaches. We found that P454 (i) binds to membranes containing anionic lipids, (ii) adopts an α-helical structure oriented in plane with respect to the lipid bilayer, and (iii) permeabilizes vesicles. We propose that the region encompassing the helix 454-485 of CyaA may insert into target cell membrane and induce a local destabilization of the lipid bilayer, thus favoring the translocation of the catalytic domain across the plasma membrane.

Original publication

DOI

10.1074/jbc.m113.508838

Type

Journal article

Journal

The Journal of biological chemistry

Publication Date

11/2013

Volume

288

Pages

32585 - 32598

Addresses

From the Institut Pasteur, CNRS UMR 3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, 28 Rue du Dr. Roux, 75724 Paris Cedex 15, France.

Keywords

Cell Membrane, Humans, Bordetella pertussis, Adenylate Cyclase Toxin, Lipid Bilayers, Peptides, Bacterial Proteins, Protein Structure, Secondary, Protein Binding, Protein Transport