Aluminum inhibits phosphatidic acid formation by blocking the phospholipase C pathway

Planta ◽  
2006 ◽  
Vol 225 (2) ◽  
pp. 393-401 ◽  
Author(s):  
Ana Ramos-Díaz ◽  
Ligia Brito-Argáez ◽  
Teun Munnik ◽  
S. M. Teresa Hernández-Sotomayor
Keyword(s):  
Phosphatidic Acid ◽  
Phospholipase C ◽  
Acid Formation

scholarly journals Action of guanosine 5′-[β-thio]diphosphate on thrombin-induced activation and Ca2+ mobilization in saponin-permeabilized and intact human platelets

1988 ◽  
Vol 255 (3) ◽  
pp. 885-893 ◽  
Author(s):  
K S Authi ◽  
G H R Rao ◽  
B J Evenden ◽  
N Crawford
Keyword(s):  
Phosphatidic Acid ◽  
Phospholipase C ◽  
G Protein ◽  
Protein Function ◽  
Low Dose ◽  
Shape Change ◽  
Acid Formation ◽  
Functional Responses ◽  
Permeabilized Cells ◽  
Fura 2

The non-hydrolysable guanine analogues guanosine 5′-[gamma-thio]triphosphate (GTP[S]) and guanosine 5′-[beta-thio]diphosphate (GDP[S]) have been used extensively (as promoters and inhibitors respectively) to probe the importance of G-protein function. We report on the use of GDP[S] in permeabilized and intact platelets. The stimulatory analogue GTP[S] (9-60 microM) induces shape change, aggregation and 5-hydroxy[14C]-tryptamine secretion when added to saponin (12-14 micrograms/ml)-permeabilized platelets, but not to intact platelets. In line with the activation responses in permeabilized cells, GTP[S] induces an increase in [32P]-phosphatidic acid, which is indicative of phospholipase C activity. GDP[S] (greater than 400 microM) totally inhibits GTP[S] (90 microM)-stimulated phospholipase C activity and functional responses in saponized platelets. GDP[S] (1 mM) was also effective at inhibiting low-dose thrombin (0.1 unit/ml)-induced aggregation and secretion responses (without affecting shape change) in permeabilized platelets with inhibition of [32P]-phosphatidic acid formation. At higher doses of thrombin (greater than 0.5 unit/ml), both functional responses and [32P]phosphatidic acid formation are restored in the presence of GDP[S]. Studies on intact cells revealed that GDP[S] was as effective at inhibiting low-dose thrombin-induced functional responses as in the permeabilized cells, but there was no inhibition of [32P]phosphatidic acid formation, indicating that the agent is nonmembrane-penetrating. This reflected the fact that GDP[S] has additional inhibitory sites on the surface of platelets. In Fura-2-loaded cells GDP[S] inhibited thrombin-induced Ca2+ mobilization, as measured by Fura-2 fluorescence, in a dose-dependent manner. In studies with and without Ca2+ present on the outside, the effect of GDP[S] was to block Ca2+ influx. These studies indicate that, although GDP[S] is a valuable tool in studying G-protein function in permeabilized cells, it also has inhibitory activities on the surface of platelets, and one of these has been identified as an effect on the Ca2+-influx channel after agonist stimulation.

Evidence for two mechanisms of thrombin-induced platelet activation: one proteolytic, one receptor mediated

1989 ◽  
Vol 67 (7) ◽  
pp. 332-336 ◽  
Author(s):  
Archibald McNicol ◽  
Jon M. Gerrard ◽  
D. Euan MacIntyre
Keyword(s):  
Phosphatidic Acid ◽  
Phospholipase C ◽  
Platelet Reactivity ◽  
Platelet Activating Factor ◽  
Receptor Activation ◽  
Acid Formation ◽  
Phosphoinositide Metabolism ◽  
Co Addition ◽  
The Individual ◽  
Dual Mechanism

The possibility that thrombin-induced platelet reactivity could occur via both a receptor-related and a proteolytic process was examined. Thrombin elicited the formation of considerably more [32P)phosphatidic acid (an index of phospholipase C catalysed phosphoinositide metabolism) than did platelet activating factor, 5-hydroxytryptamine, ADP, and the thromboxane A2 analogue EP171, when these agents were added either alone or in combination. Co-addition of thrombin and EP171 did not evoke significantly more [32P]phosphatidic acid than did thrombin alone. The protease inhibitor leupeptin, decreased but did not abolish [32P]phosphatidic acid formation elicited by either thrombin alone or thrombin in combination with EP171. The serine protease, trypsin, stimulated an increase in [32P]phosphatidic acid and this effect was additive with that of EP171. This augmentation by trypsin of EP171-induced [32P]phosphatidic acid formation was inhibited by leupeptin. These results are consistent with the concept that thrombin-induced activation of phospholipase C occurs by two distinct mechanisms: one via proteolysis, which is sensitive to leupeptin, and the other via receptor activation, a process shared by EP171. The individual components of this dual mechanism can be mimicked by the co-addition of a receptor-directed agonist (EP171) and a proteolytic agent (trypsin).Key words: platelet, thrombin, proteolysis, phosphoinositide.

scholarly journals Structural Determinants for Phosphatidic Acid Regulation of Phospholipase C-β1

2006 ◽  
Vol 281 (44) ◽  
pp. 33087-33094 ◽  
Author(s):  
Elliott M. Ross ◽  
Dania Mateu ◽  
Aldrin V. Gomes ◽  
Carlos Arana ◽  
Thanh Tran ◽  
...  
Keyword(s):  
Phosphatidic Acid ◽  
Phospholipase C ◽  
Structural Determinants

Study of the Involvement of Phosphatidic Acid Formation in the Expression of Wound-Responsive Genes in Cotton

Lipids ◽  
2018 ◽  
Vol 53 (6) ◽  
pp. 589-599
Author(s):  
Angeliki Bourtsala ◽  
Ioannis Dafnis ◽  
Angeliki Chroni ◽  
Theodora Farmaki ◽  
Dia Galanopoulou
Keyword(s):  
Phosphatidic Acid ◽  
Acid Formation

Phosphatidic acid production in chitosan-elicited tomato cells, via both phospholipase D and phospholipase C/diacylglycerol kinase, requires nitric oxide

2011 ◽  
Vol 168 (6) ◽  
pp. 534-539 ◽  
Author(s):  
Nicolás Raho ◽  
Leonor Ramirez ◽  
M. Luciana Lanteri ◽  
Gabriela Gonorazky ◽  
Lorenzo Lamattina ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Phosphatidic Acid ◽  
Phospholipase C ◽  
Phospholipase D ◽  
Acid Production ◽  
Diacylglycerol Kinase

scholarly journals Activation of phospholipase C and prostaglandin synthesis by [arginine]vasopressin in cultures

1984 ◽  
Vol 223 (3) ◽  
pp. 855-859 ◽  
Author(s):  
J Pfeilschifter ◽  
A Kurtz ◽  
C Bauer
Keyword(s):  
Arachidonic Acid ◽  
Phosphatidic Acid ◽  
Prostaglandin E2 ◽  
Phospholipase C ◽  
Arginine Vasopressin ◽  
Mesangial Cells ◽  
Significant Loss ◽  
Prostaglandin Synthesis ◽  
Phosphatidylinositol 4 ◽  
In Cells

[Arginine]vasopressin (AVP) stimulates maximal prostaglandin E2 production in cultured rat renal mesangial cells within 2 min. As early as 10s after addition of AVP (10(-6)M) a significant loss of radioactivity from phosphatidylinositol 4,5-bisphosphate but not from phosphatidylinositol 4-phosphate and phosphatidylinositol was observed in cells prelabelled with 32Pi. Cells labelled with [14C]arachidonic acid showed an increase of label in 1,2-diacylglycerol after 15 s and in phosphatidic acid after 30 s upon stimulation with AVP. Pretreatment of the cells with indomethacin (10(-5)M) did not abolish the effect of AVP on the increased labelling of phosphatidic acid.

The acylation of 1-acyl-sn-glycero-3-phosphate by neuronal nuclei and microsomal fractions of immature rabbit cerebral cortex

1990 ◽  
Vol 68 (3) ◽  
pp. 641-647 ◽  
Author(s):  
R. Roy Baker ◽  
H.-Y. Chang
Keyword(s):  
Cerebral Cortex ◽  
Phosphatidic Acid ◽  
Lysophosphatidic Acid ◽  
Monounsaturated Fatty Acids ◽  
Acid Formation ◽  
Nuclear Fraction ◽  
Neuronal Nucleus ◽  
Neuronal Nuclei ◽  
Low Concentrations ◽  
Rabbit Cerebral Cortex

The acylation of 1-acyl-sn-glycero-3-phosphate to form phosphatidic acid was studied using a neuronal nuclear fraction N1 and microsomal fractions P3, R (rough), S (smooth), and P (neuronal microsomes from nerve cell bodies) isolated from cerebral cortices of 15-day-old rabbits. The assays contained this lysophospholipid, ATP, CoA, MgCl2, NaF, dithiothreitol, and radioactive palmitate, oleate, or arachidonate. Of the subfractions, N1 and R had the highest specific activities (expressed per micromole phospholipid in the fraction). The rates with oleate were two to four times the values seen for phosphatidic acid formation from sn-[3H]glycero-3-phosphate and oleoyl-CoA. Using oleate or palmitate, fraction R had superior specific rates to N1 at low lysophosphatidic acid concentrations. With increasing lysophospholipid concentrations the specific rates of N1 and R came closer together and maintained at least a twofold superiority over fraction P. Fraction S had the lowest specific rates of phosphatidic acid formation. Fractions N1, R, and P showed a preference for palmitate and oleate over arachidonate, particularly at low concentrations of lysophosphatidic acid. For N1 and R, the preference was also more marked at higher concentrations of fatty acid. Thus a selectivity for saturated and monounsaturated fatty acids was shown in the formation of phosphatidic acid, as was a concentration of acylating activity in the neuronal nucleus and the rough endoplasmic reticulum.Key words: 1-acyl-sn-glycero-3-phosphate, acylation, neuronal nuclei, microsomes, cerebral cortex.

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