Phospholipase C activator m-3M3FBS affects Ca2+ homeostasis independently of phospholipase C activation.
In this study, we have investigated responses to the phospholipase C (PLC) activator m-3M3FBS in SH-SY5Y human neuroblastoma cells. As measured using fura-2, m-3M3FBS caused a slowly developing - full response was obtained within 4-6 min - Ca(2+) elevation both in the presence and absence of extracellular Ca(2+), indicating Ca(2+) release from intracellular stores, putatively from endoplasmic reticulum and mitochondria. PLC activity was also measured using two methods, the classical ion-exchange separation and the more novel fluorescent real-time method. In the time frame in which m-3M3FBS caused Ca(2+) elevation (up to 7 min), no PLC activation was detected. Instead, more than 20 min were required to see any inositol phosphate generation in response to m-3M3FBS. m-3M3FBS also interfered with store-operated Ca(2+) influx and Ca(2+) extrusion. In conclusion, m-3M3FBS cannot be considered either potent or specific PLC activator.
Division of Physiology, Department of Neuroscience, Uppsala University, BMC, PO Box 572, SE-75123 Uppsala, Sweden.
Jelena
J
Krjukova
Tomas
T
Holmqvist
Alexander S
AS
Danis
Karl E O
KE
Akerman
Jyrki P
JP
Kukkonen
D000818:Animals; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism*; D045744:Cell Line, Tumor; D006224:Cricetinae; D003592:Cytophotometry; D004789:Enzyme Activation / Q000187:drug effects; D020536:Enzyme Activators / Q000494:pharmacology*; D004963:Estrenes / Q000494:pharmacology; D005260:Female; D005456:Fluorescent Dyes; D016257:Fura-2; D006706:Homeostasis / Q000187:drug effects*; D006801:Humans; D018721:Muscarinic Agonists / Q000494:pharmacology; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D011760:Pyrrolidinones / Q000494:pharmacology; D011976:Receptors, Muscarinic / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology*; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000096926:Benzenesulfonamides
D002118:Calcium; D020536:Enzyme Activators; D004963:Estrenes; D005456:Fluorescent Dyes; D016257:Fura-2; D018721:Muscarinic Agonists; D019269:Phosphatidylinositol 4,5-Diphosphate; D011760:Pyrrolidinones; D011976:Receptors, Muscarinic; D013449:Sulfonamides; D010738:Type C Phospholipases; C473783:2,4,6-trimethyl-N-(meta-3-trifluoromethylphenyl)benzenesulfonamide; D000096926:Benzenesulfonamides; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione