scholarly journals Rat brain cytosol contains a factor which reconstitutes guanine-nucleotide-binding-protein-regulated phospholipase-D activation in HL60 cells previously permeabilized with streptolysin O

1993 ◽  
Vol 215 (2) ◽  
pp. 389-396 ◽  
Author(s):  
Blandine GENY ◽  
Amanda FENSOME ◽  
Shamshad COCKCROFT
Keyword(s):  
Rat Brain ◽  
Phospholipase D ◽  
Binding Protein ◽  
Nucleotide Binding ◽  
Guanine Nucleotide ◽  
Guanine Nucleotide Binding Protein ◽  
Hl60 Cells ◽  
Streptolysin O ◽  
Guanine Nucleotide Binding ◽  
Brain Cytosol

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

1991 ◽  
Vol 2 (12) ◽  
pp. 1011-1019 ◽  
Author(s):  
M Liscovitch ◽  
Y Eli
Keyword(s):  
Phospholipase D ◽  
Binding Protein ◽  
Nucleotide Binding ◽  
Intracellular Concentration ◽  
Guanine Nucleotide ◽  
Guanine Nucleotide Binding Protein ◽  
Specific Product ◽  
Guanine Nucleotide Binding ◽  
Transphosphatidylation Reaction ◽  
Gamma S

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.

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