Inhibition of phosphatidylserine synthesis by glutamate, acetylcholine, thapsigargin and ionophore A23187 in glioma C6 cells.
Phosphatidylserine synthesis was studied in glioma C6 cells with [14C]serine and in the presence or absence of agents which increase the level of [Ca2+]i. It was found that glutamate and acetylcholine inhibited this synthesis by up to 40%, whereas thapsigargin and the ionophore A23187 inhibited by up to 70%. The inhibitory effect of thapsigargin and the A23187 was observed in Ca(2+)-free medium. The data show that the inhibition of this synthesis is caused by the Ca(2+)-depletion from endoplasmic reticulum, suggesting that the synthesis of phosphatidylserine occurs on the luminal side of these structures and can be regulated by transmembrane signaling systems.
Dept. of Cellular Biochemistry, Nencki Institute of Experimental Biology, Warsaw, Poland.
M
M
Czarny
P
P
Sabała
A
A
Ucieklak
L
L
Kaczmarek
J
J
Barańska
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002122:Calcium Chloride / Q000494:pharmacology; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D004305:Dose-Response Relationship, Drug; D004492:Edetic Acid / Q000494:pharmacology; D016257:Fura-2; D005910:Glioma; D005971:Glutamates / Q000494:pharmacology*; D018698:Glutamic Acid; D007700:Kinetics; D010718:Phosphatidylserines / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D013729:Terpenes / Q000494:pharmacology*; D019284:Thapsigargin; D014407:Tumor Cells, Cultured
D005971:Glutamates; D010718:Phosphatidylserines; D013729:Terpenes; D000001:Calcimycin; D018698:Glutamic Acid; D019284:Thapsigargin; D004492:Edetic Acid; D000252:Calcium-Transporting ATPases; D002122:Calcium Chloride; D000109:Acetylcholine; D002118:Calcium; D016257:Fura-2