Possible involvement of botulinum ADP-ribosyltransferase sensitive low molecular G-protein on 5-hydroxytryptamine (5-HT)-induced inositol phosphates formation in 5-HT2c cDNA transfected cells.
To clarify the involvement of botulinum ADP-ribosyltransferase sensitive low molecular G-proteins in 5-hydroxytryptamine (5-HT)-induced stimulation of phosphatidylinositol turnover, we examined the effects of 5-HT on inositol phosphates formation in COS 7 cells transfected with 5-HT2c receptor cDNA, but did not in non-transfected or vector-transfected cells. A typical 5-HT2c receptor antagonist mianserin (0.3-3 microM) inhibited the 5-HT-induced inositol phosphates formation. Treatment with botulinum toxin D preparation (20 micrograms/ml, 8 h) that contained botulinum C3 ADP-ribosyltransferase, blocked the 5-HT-induced inositol phosphate formation, although botulinum toxin A preparation that did not contain the enzyme did not have an influence. These results support our previous findings suggesting that low molecular weight G-proteins ADP-ribosylated by botulinum ADP-ribosyltransferase are involved in phospholipase C activity.
Tohda
M
M
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
Tohda
C
C
Oda
H
H
Nomura
Y
Y
D036002:ADP Ribose Transferases / Q000494:pharmacology*; D000818:Animals; D001905:Botulinum Toxins / Q000494:pharmacology*; D018076:DNA, Complementary / Q000235:genetics; D004586:Electrophoresis; D019204:GTP-Binding Proteins / Q000378:metabolism*; D007295:Inositol Phosphates / Q000378:metabolism*; D008803:Mianserin / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology; D014162:Transfection
D018076:DNA, Complementary; D007295:Inositol Phosphates; D008803:Mianserin; D012701:Serotonin; D036002:ADP Ribose Transferases; C063007:exoenzyme C3, Clostridium botulinum; D001905:Botulinum Toxins; D019204:GTP-Binding Proteins