Perforin-2 clockwise hand-over-hand pre-pore to pore transition mechanism.

TitlePerforin-2 clockwise hand-over-hand pre-pore to pore transition mechanism.
Publication TypeJournal Article
Year of Publication2022
AuthorsJiao F, Dehez F, Ni T, Yu X, Dittman JS, Gilbert R, Chipot C, Scheuring S
JournalNat Commun
Date Published2022 08 26
KeywordsAnimals, Cell Membrane, Macrophages, Mammals, Microscopy, Atomic Force, Molecular Dynamics Simulation, Perforin, Pore Forming Cytotoxic Proteins

Perforin-2 (PFN2, MPEG1) is a pore-forming protein that acts as a first line of defense in the mammalian immune system, rapidly killing engulfed microbes within the phagolysosome in macrophages. PFN2 self-assembles into hexadecameric pre-pore rings that transition upon acidification into pores damaging target cell membranes. Here, using high-speed atomic force microscopy (HS-AFM) imaging and line-scanning and molecular dynamics simulation, we elucidate PFN2 pre-pore to pore transition pathways and dynamics. Upon acidification, the pre-pore rings (pre-pore-I) display frequent, 1.8 s-1, ring-opening dynamics that eventually, 0.2 s-1, initiate transition into an intermediate, short-lived, ~75 ms, pre-pore-II state, inducing a clockwise pre-pore-I to pre-pore-II propagation. Concomitantly, the first pre-pore-II subunit, undergoes a major conformational change to the pore state that propagates also clockwise at a rate ~15 s-1. Thus, the pre-pore to pore transition is a clockwise hand-over-hand mechanism that is accomplished within ~1.3 s. Our findings suggest a clockwise mechanism of membrane insertion that with variations may be general for the MACPF/CDC superfamily.

Alternate JournalNat Commun
PubMed ID36028507
PubMed Central IDPMC9418332
Grant ListDP1 AT010874 / AT / NCCIH NIH HHS / United States
R01 NS110790 / NS / NINDS NIH HHS / United States
090532/Z/09/Z / WT_ / Wellcome Trust / United Kingdom