Direct transmembrane interaction between actin and the pore-competent, cholesterol-dependent cytolysin pneumolysin

Sabrina Hupp, Christina Förtsch, Carolin Wippel, Jiangtao Ma, Tim Mitchell, Asparouh I. Iliev

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)
227 Downloads (Pure)

Abstract

The eukaryotic actin cytoskeleton is an evolutionarily well-established pathogen target, as a large number of bacterial factors disturb its dynamics to alter the function of the host cells. These pathogenic factors modulate or mimic actin effector proteins or they modify actin directly, leading to an imbalance of the precisely regulated actin turnover. Here, we show that the pore-forming, cholesterol-dependent cytolysin pneumolysin (PLY), a major neurotoxin of Streptococcus pneumoniae, has the capacity to bind actin directly and to enhance actin polymerisation in vitro. In cells, the toxin co-localised with F-actin shortly after exposure, and this direct interaction was verified by Förster resonance energy transfer. PLY was capable of exerting its effect on actin through the lipid bilayer of giant unilamellar vesicles, but only when its pore competence was preserved. The dissociation constant of G-actin binding to PLY in a biochemical environment was 170–190 nM, which is indicative of a high-affinity interaction, comparable to the affinity of other intracellular actin-binding factors. Our results demonstrate the first example of a direct interaction of a pore-forming toxin with cytoskeletal components, suggesting that the cross talk between pore-forming cytolysins and cells is more complex than previously thought.
Original languageEnglish
Pages (from-to)636-646
JournalJournal of Molecular Biology
Volume425
Issue number3
Early online date3 Dec 2012
DOIs
Publication statusPublished - 8 Feb 2013

Keywords

  • actin
  • cholesterol-dependent cytolysin
  • membrane
  • pneumolysin
  • pore-forming toxin

Fingerprint

Dive into the research topics of 'Direct transmembrane interaction between actin and the pore-competent, cholesterol-dependent cytolysin pneumolysin'. Together they form a unique fingerprint.

Cite this