Some β-PFTs such as clostridial ε-toxin and Clostridium perfringens Enterotoxin (CPE) bind to the cell membrane via specific receptors - possibly certain claudins for CPE,[REF] possibly GPI anchors or other sugars for ε-toxin - these receptors help raise the local concentration of the toxins, allowing oligomerisation and pore formation.
When the pore is formed, the tight regulation of what can and cannot enter/leave a cell is disrupted.