Binding of botulinum type B neurotoxin to Chinese hamster ovary cells transfected with rat synaptotagmin II cDNA.
We have previously identified synaptotagmin, a synaptic vesicle membrane protein from rat brain, as a binding protein for Clostridium botulinum type B neurotoxin. In this report, rat synaptotagmin II was expressed by transfection in Chinese hamster ovary cells and interaction with the neurotoxin was studied. In stable transfectants, the NH(2)-terminal region of synaptotagmin was exposed to the extracellular medium. Synaptotagmin-expressing cells were shown to possess an extremely low binding activity for the radiodinated toxin. However, toxin-binding was markedly increased to cells which had been treated with gangliosides G T1b or G D1a. In synapses, the intravesicular NH(2)-terminus of synaptotagmin becomes exposed at the cell surface after following exocytosis. These findings suggest that the NH(2)-terminal domain of synaptotagmin II forms the binding site for type B neurotoxin by associating with specific gangliosides in presynaptic plasma membranes.
Nishiki
T
T
Department of Veterinary Science, College of Agriculture, Osaka Prefecture University, Japan.
Tokuyama
Y
Y
Kamata
Y
Y
Nemoto
Y
Y
Yoshida
A
A
Sekiguchi
M
M
Takahashi
M
M
Kozaki
S
S
D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D001667:Binding, Competitive / Q000502:physiology; D001905:Botulinum Toxins / Q000378:metabolism* / Q000494:pharmacology; D019274:Botulinum Toxins, Type A; D016466:CHO Cells / Q000737:chemistry / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics; D006224:Cricetinae; D018076:DNA, Complementary; D007457:Iodine Radioisotopes; D051379:Mice; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000235:genetics* / Q000276:immunology; D051381:Rats; D050861:Synaptotagmin II; D014162:Transfection
D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D018076:DNA, Complementary; D007457:Iodine Radioisotopes; D009419:Nerve Tissue Proteins; D050861:Synaptotagmin II; C494263:Syt2 protein, mouse; C494264:Syt2 protein, rat; C096323:rimabotulinumtoxinB; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A