Abstract
The majority of Methicillin-resistant Staphylococcus aureus (MRSA) bacteria produce pore forming toxins, specifically targeting white blood cells (leucocytes), which help infecting cells avoid immune response. Panton-Valentine Leukocidin is one of these toxins and comprises two protein subunits, LukS and LukF, which interact with the human C5a receptor (hC5aR) to form holes in the cell membrane and kill the cell. We have labelled LukS/F and hC5aR with different fluorophores and imaged their interaction in live mammalian cells using rapid single-molecule total internal reflection fluorescence (TIRF) microscopy. We find LukS binds first to hC5aR and forms tetramers within hC5aR clusters. LukF is recruited to these LukS-hC5aR complexes leading to lytic pore formation and simultaneous dissociation of LukS-LukF from hC5aR. Our findings support a crystallographic heterooctamer model but provide a new view on the kinetics of these crucial virulence factors and their interactions with live cells.
Original language | English |
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Pages (from-to) | 381 |
Number of pages | 1 |
Journal | European Biophysics Journal |
Volume | 46 |
Issue number | S1 |
DOIs | |
Publication status | Published - 1 Jul 2017 |
Keywords
- complement component C5a receptor
- endogenous compound
- toxin
- virulence factor
- channel gating
- chemical reaction kinetics
- crystal structure
- dissociation
- human
- kinetics
- mammal cell
- microscopy