High sensitivity of mouse neuronal cells to tetanus toxin requires a GPI-anchored protein

Tetanus neurotoxin (TeNT) produced by Clostridium tetani specifically cleav es VAMP/synaptobrevin (VAMP) in central neurons, thereby causing inhibition of neurotransmitter release and ensuing spastic paralysis. Although polysi alogangliosides act as components of the neurotoxin binding sites on neuron s, evidence has accumulated indicating that a protein moiety is implicated as a receptor of TeNT. We have observed that treatment of cultured mouse ne uronal cells with the phosphatidylinositol-specific phospholipase C (PIPLC) inhibited TeNT-induced cleavage of VAMP. Also, we have shown that the bloc king effects of TeNT on neuroexocytosis can be prevented by incubation of P urkinje cell preparation with PIPLC. In addition, treatment of cultured mou se neuronal cells with cholesterol sequestrating agents such as nystatin an d filipin, which disrupt clustering of GPI-anchored proteins in lipid rafts , prevented intraneuronal VAMP cleavage by TeNT. Our results demonstrate th at high sensitivity of neurons to TeNT requires rafts and. one or more GPI- anchored protein(s) which act(s) as a pivotal receptor for the neurotoxin. (C) 2001 Elsevier Science.