Single-molecule analysis of the entire perfringolysin O pore formation pathway

Conall Mc Guinness, James C. Walsh, Charles Bayly-Jones, Michelle A. Dunstone, Michelle P. Christie, Craig J. Morton, Michael W. Parker, Till Bocking

Research output: Contribution to journalArticleResearchpeer-review

4 Citations (Scopus)

Abstract

The cholesterol-dependent cytolysin perfringolysin O (PFO) is secreted by Clostridium perfringens as a bacterial virulence factor able to form giant ring-shaped pores that perforate and ultimately lyse mammalian cell membranes. To resolve the kinetics of all steps in the assembly pathway, we have used single-molecule fluorescence imaging to follow the dynamics of PFO on dye- loaded liposomes that lead to opening of a pore and release of the encapsulated dye. Formation of a long-lived membrane-bound PFO dimer nucleates the growth of an irreversible oligomer. The growing oligomer can insert into the membrane and open a pore at stoichiometries ranging from tetramers to full rings (~35 mers), whereby the rate of insertion increases linearly with the number of subunits. Oligomers that insert before the ring is complete continue to grow by monomer addi¬tion post insertion. Overall, our observations suggest that PFO membrane insertion is kinetically controlled.

Original languageEnglish
Article numbere74901
Number of pages34
JournaleLife
Volume11
DOIs
Publication statusPublished - 2022

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