Botulinum ADP-ribosyltransferase C3 induces elevation of the vitelline coat of ascidian eggs.
Botulinum exoenzyme C3 ADP-ribosylates a 23 kDa protein of unfertilized eggs of the ascidian, Halocynthia roretzi. Microinjection of C3 into the eggs induced elevation of the egg vitelline coat. Co-injection of heparin or EGTA with C3 inhibited the inducing effect of C3. The vitelline coat of eggs which had been previously co-injected with heparin and C3 was elevated by addition of calcium ionophore, but not by insemination. C3 also induced an increased formation of inositol 1,4,5-triphosphate (IP3) in ascidian egg membranes. Thus the ADP-ribosylation of small GTP-binding protein by C3 seems to be responsible for elevation of the vitelline coat of ascidian eggs through IP3 formation and intracellular calcium mobilization.
Toratani
S
S
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
Katada
T
T
Yokosawa
H
H
D036002:ADP Ribose Transferases / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000818:Animals; D001905:Botulinum Toxins; D000001:Calcimycin / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D005260:Female; D005306:Fertilization; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D008565:Membrane Proteins / Q000187:drug effects / Q000378:metabolism*; D008845:Microinjections; D008970:Molecular Weight; D010063:Ovum / Q000187:drug effects / Q000378:metabolism*; D014561:Urochordata / Q000187:drug effects / Q000378:metabolism*; D014817:Vitelline Membrane / Q000187:drug effects / Q000378:metabolism*
D008565:Membrane Proteins; D000246:Adenosine Diphosphate Ribose; D000001:Calcimycin; D004533:Egtazic Acid; D015544:Inositol 1,4,5-Trisphosphate; D036002:ADP Ribose Transferases; C063007:exoenzyme C3, Clostridium botulinum; D001905:Botulinum Toxins