Tetanus toxin mechanism of action in Torpedo electromotor system: a study on different steps in the intoxication process.
The mechanism of action of tetanus toxin was characterized in the electromotor system of Torpedo marmorata either at peripheral and central nervous system. The consecutive steps of the intoxication pathway were observed: (i) [125I]tetanus toxin specifically bound to neuronal plasma membranes isolated both from electric organ and electric lobe of Torpedo, exhibiting one and two binding sites respectively; (ii) [125I]tetanus toxin was internalized into nerve terminals and retrogradely transported to the electric lobe after its injection in the electric organ; (iii) finally, intracellular effect of tetanus toxin was studied either at electric organ and electric lobe membrane fractions. In both preparations tetanus toxin cleaved synaptobrevin, as detected by immunoblotting methods. In conclusion, our findings exhibit the presence of two different populations of acceptors for tetanus toxin in central and peripheral nervous system and show that synaptobrevin cleavage may account for intracellular toxicity in Torpedo.
Herreros
J
J
Departament de Biologia Cel.lular i Anatomia Patològica, Facultat de Medicina, Hospital de Bellvitge, Universitat de Barcelona, Spain.
Blasi
J
J
Arribas
M
M
Marsal
J
J
D000818:Animals; D001345:Autoradiography; D001665:Binding Sites; D004305:Dose-Response Relationship, Drug; D004557:Electric Organ / Q000187:drug effects*; D008564:Membrane Potentials / Q000187:drug effects; D009046:Motor Neurons / Q000187:drug effects*; D013572:Synaptic Vesicles / Q000187:drug effects; D013744:Tetanus Toxin / Q000633:toxicity*; D014101:Torpedo
D013744:Tetanus Toxin