Biomaterial Database

Ca2+ inhibits guanine nucleotide-activated phospholipase D in neural-derived NG108-15 cells. 1991

M Liscovitch, and Y Eli

Department of Hormone Research, Weizmann Institute of Science, Rehovot, Israel.

We have investigated the regulation of phospholipase D (PLD) activity by guanine nucleotides and Ca2+ in cells of the NG108-15 neuroblastoma X glioma line that were permeabilized with digitonin. The nonhydrolyzable GTP analogue guanosine-5'-O-(3-thiotriphosphate) (GTP gamma S) caused a nearly sixfold increase (EC50 = 3 microM) in production of [3H]phosphatidylethanol (specific product of the PLD transphosphatidylation reaction). Other GTP analogues were less effective than GTP gamma S, and guanosine-5'-O-(2-thiodiphosphate) inhibited PLD activation by GTP gamma S. Both basal and GTP gamma S-stimulated PLD activities were potentiated by MgATP and Mg2+. Adenosine-5'-O-(3-thiotriphosphate) and ADP also potentiated the effect of GTP gamma S, but non-phosphorylating analogues of ATP had no such effect. The activation of PLD by GTP gamma S did not require Ca2+ and was independent of free Ca2+ ions up to a concentration of 100 nM (resting intracellular concentration). Higher Ca2+ concentrations (greater than or equal to 1 microM) completely inhibited PLD activation by GTP gamma S. It is concluded that elevated intracellular Ca2+ concentrations may negatively modulate PLD activation by a guanine nucleotide-binding protein, thus affecting receptor-PLD coupling in neural-derived cells.

UI	MeSH Term	Description	Entries
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D010739	Phospholipase D	An enzyme found mostly in plant tissue. It hydrolyzes glycerophosphatidates with the formation of a phosphatidic acid and a nitrogenous base such as choline. This enzyme also catalyzes transphosphatidylation reactions. EC 3.1.4.4.	Lecithinase D,Phosphatidylcholine Phosphohydrolase
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D006150	Guanine Nucleotides		Guanine Nucleotide,Guanosine Phosphates,Nucleotide, Guanine,Nucleotides, Guanine,Phosphates, Guanosine
D006160	Guanosine Triphosphate	Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.	GTP,Triphosphate, Guanosine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured
D016244	Guanosine 5'-O-(3-Thiotriphosphate)	Guanosine 5'-(trihydrogen diphosphate), monoanhydride with phosphorothioic acid. A stable GTP analog which enjoys a variety of physiological actions such as stimulation of guanine nucleotide-binding proteins, phosphoinositide hydrolysis, cyclic AMP accumulation, and activation of specific proto-oncogenes.	GTP gamma S,Guanosine 5'-(gamma-S)Triphosphate,gamma-Thio-GTP,GTPgammaS,Guanosine 5'-(3-O-Thio)Triphosphate,gamma S, GTP,gamma Thio GTP
D019204	GTP-Binding Proteins	Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.	G-Proteins,GTP-Regulatory Proteins,Guanine Nucleotide Regulatory Proteins,G-Protein,GTP-Binding Protein,GTP-Regulatory Protein,Guanine Nucleotide Coupling Protein,G Protein,G Proteins,GTP Binding Protein,GTP Binding Proteins,GTP Regulatory Protein,GTP Regulatory Proteins,Protein, GTP-Binding,Protein, GTP-Regulatory,Proteins, GTP-Binding,Proteins, GTP-Regulatory