Hydrolysis of the glycosyl-phosphatidylinositol anchors of renal microvillar peptidases by a plasma phospholipase D

1989 ◽  
Vol 17 (5) ◽  
pp. 885-886 ◽  
Author(s):  
NIGEL M. HOOPER ◽  
ANTHONY J. TURNER
Keyword(s):  
Phospholipase D ◽  
Glycosyl Phosphatidylinositol ◽  
Hydrolysis Of

scholarly journals An Explanation for the Adiponectin Paradox

2021 ◽  
Vol 14 (12) ◽  
pp. 1266
Author(s):  
Hans O. Kalkman
Keyword(s):  
Insulin Resistance ◽  
Signal Transduction ◽  
Insulin Sensitivity ◽  
Phospholipase D ◽  
Functional Consequence ◽  
Glycosyl Phosphatidylinositol ◽  
Paradoxical Situation ◽  
Hydrolysis Of ◽  
Circulating Levels ◽  
Sensitivity Functional

The adipokine adiponectin improves insulin sensitivity. Functional signal transduction of adiponectin requires at least one of the receptors AdipoR1 or AdipoR2, but additionally the glycosyl phosphatidylinositol-anchored molecule, T-cadherin. Overnutrition causes a reduction in adiponectin synthesis and an increase in the circulating levels of the enzyme glycosyl phosphatidylinositol-phospholipase D (GPI-PLD). GPI-PLD promotes the hydrolysis of T-cadherin. The functional consequence of T-cadherin hydrolysis is a reduction in adiponectin sequestration by responsive tissues, an augmentation of adiponectin levels in circulation and a (further) reduction in signal transduction. This process creates the paradoxical situation that adiponectin levels are augmented, whereas the adiponectin signal transduction and insulin sensitivity remain strongly impaired. Although both hypoadiponectinemia and hyperadiponectinemia reflect a situation of insulin resistance, the treatments are likely to be different.

Insulin does not induce the hydrolysis of a glycosyl phosphatidylinositol in rat fetal hepatocytes

Diabetes ◽  
1993 ◽  
Vol 42 (9) ◽  
pp. 1262-1272 ◽  
Author(s):  
J. M. Ruiz-Albusac ◽  
J. A. Zueco ◽  
E. Velazquez ◽  
E. Blazquez
Keyword(s):  
Glycosyl Phosphatidylinositol ◽  
Fetal Hepatocytes ◽  
Hydrolysis Of

scholarly journals The roles of phospholipase D and a GTP-binding protein in guanosine 5′-[γ-thio]triphosphate-stimulated hydrolysis of phosphatidylcholine in rat liver plasma membranes

1990 ◽  
Vol 272 (3) ◽  
pp. 749-753 ◽  
Author(s):  
K M Hurst ◽  
B P Hughes ◽  
G J Barritt
Keyword(s):  
Rat Liver ◽  
Phospholipase D ◽  
Plasma Membranes ◽  
Regulatory Protein ◽  
Gtp Binding ◽  
Liver Plasma Membranes ◽  
Low Concentrations ◽  
Rat Liver Plasma Membranes ◽  
Triton X ◽  
Hydrolysis Of

1. Guanosine 5′-[gamma-thio]triphosphate (GTP[S]) stimulated by 50% the rate of release of [3H]choline and [3H]phosphorylcholine in rat liver plasma membranes labelled with [3H]choline. About 70% of the radioactivity released in the presence of GTP[S] was [3H]choline and 30% was [3H]phosphorylcholine. 2. The hydrolysis of phosphorylcholine to choline and the conversion of choline to phosphorylcholine did not contribute to the formation of [3H]choline and [3H]phosphorylcholine respectively. 3. The release of [3H]choline from membranes was inhibited by low concentrations of SDS or Triton X-100. Considerably higher concentrations of the detergents were required to inhibit the release of [3H]phosphorylcholine. 4. Guanosine 5′-[beta gamma-imido]triphosphate and guanosine 5′-[alpha beta-methylene]triphosphate, but not adenosine 5′-[gamma-thio]-triphosphate, stimulated [3H]choline release to the same extent as did GTP[S]. The GTP[S]-stimulated [3H]choline release was inhibited by guanosine 5′-[beta-thio]diphosphate, GDP and GTP but not by GMP. 5. It is concluded that, in rat liver plasma membranes, (a) GTP[S]-stimulated hydrolysis of phosphatidylcholine is catalysed predominantly by phospholipase D with some contribution from phospholipase C, and (b) the stimulation of phosphatidylcholine hydrolysis by GTP[s] occurs via a GTP-binding regulatory protein.

scholarly journals Phorbol ester selectively stimulates the phospholipase D-mediated hydrolysis of phosphatidylethanolamine in multidrug-resistant MCF-7 human breast carcinoma cells

1994 ◽  
Vol 302 (3) ◽  
pp. 649-654 ◽  
Author(s):  
Z Kiss ◽  
M Tomono ◽  
W B Anderson
Keyword(s):  
Breast Carcinoma ◽  
Phospholipase D ◽  
Multidrug Resistant ◽  
Carcinoma Cells ◽  
Human Breast Carcinoma ◽  
Human Breast ◽  
Breast Carcinoma Cells ◽  
Human Breast Carcinoma Cells ◽  
Hydrolysis Of ◽  
Mcf 7

The phospholipase D (PLD)-mediated synthesis of phosphatidylethanol (PtdEtOH) and the hydrolysis of phosphatidylethanolamine (PtdEtn) and phosphatidylcholine (PtdCho) were examined in drug-sensitive and multidrug-resistant lines of MCF-7 human breast carcinoma cells. In drug-sensitive (MCF-7/WT) cells, the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA) failed to enhance either the synthesis of PtdEtOH or the hydrolysis of either phospholipid. In the drug-resistant (MCF-7/MDR) cells, 100 nM PMA greatly enhanced both the synthesis of PtdEtOH (approximately 21-fold) and the hydrolysis of PtdEtn (approximately 29-fold), but had no effect on the hydrolysis of PtdCho. The PLD activators sphingosine and H2O2 were found to elicit only a slight (1.28-1.4-fold) stimulatory effect on PtdCho hydrolysis in both the MCF-7/WT and MCF-7/MDR cell types, and had only a small effect on PtdEtn hydrolysis in the MCF-7/WT cells as well. However, these agents significantly (approximately 2.6-3.5-fold) stimulated PtdEtn hydrolysis in the MCF-7/MDR cells. These data indicate that MCF-7/MDR cells contain a PtdEtn-specific PLD activity which can be selectively stimulated by PMA, sphingosine and H2O2.

scholarly journals Mutating His29, His125, His133 or His158 abolishes glycosylphosphatidylinositol-specific phospholipase D catalytic activity

2005 ◽  
Vol 391 (2) ◽  
pp. 285-289 ◽  
Author(s):  
Nandita S. Raikwar ◽  
Rosario F. Bowen ◽  
Mark A. Deeg
Keyword(s):  
Catalytic Activity ◽  
Phospholipase D ◽  
Catalytic Domain ◽  
Computer Modelling ◽  
Critical Role ◽  
Biochemical Properties ◽  
Catalytic Site ◽  
Wild Type ◽  
Histidine Residues ◽  
Hydrolysis Of

Glycosylphosphatidylinositol (GPI)-specific phospholipase D (GPI-PLD) specifically cleaves GPIs. This phospholipase D is a secreted protein consisting of two domains: an N-terminal catalytic domain and a predicted C-terminal β-propeller. Although the biochemical properties of GPI-PLD have been extensively studied, its catalytic site has not been identified. We hypothesized that a histidine residue(s) may play a critical role in the catalytic activity of GPI-PLD, based on the observations that (i) Zn2+, which utilizes histidine residues for binding, is required for GPI-PLD catalytic activity, (ii) a phosphohistidine intermediate is involved in phospholipase D hydrolysis of phosphatidylcholine, (iii) computer modelling suggests a catalytic site containing histidine residues, and (iv) our observation that diethyl pyrocarbonate, which modifies histidine residues, inhibits GPI-PLD catalytic activity. Individual mutation of the ten histidine residues to asparagine in the catalytic domain of murine GPI-PLD resulted in three general phenotypes: not secreted or retained (His56 or His88), secreted with catalytic activity (His34, His81, His98 or His219) and secreted without catalytic activity (His29, His125, His133 or His158). Changing His133 but not His29, His125 or His158 to Cys resulted in a mutant that retained catalytic activity, suggesting that at least His133 is involved in Zn2+ binding. His133 and His158 also retained the biochemical properties of wild-type GPI-PLD including trypsin cleavage pattern and phosphorylation by protein kinase A. Hence, His29, His125, His133 and His158 are required for GPI-PLD catalytic activity.

scholarly journals Insulin Promotes the Hydrolysis of a Glycosyl Phosphatidylinositol in Cultured Rat Astroglial Cells

2002 ◽  
Vol 68 (1) ◽  
pp. 10-19 ◽  
Author(s):  
Juan Miguel Ruiz-Albusac ◽  
Esther Velázquez ◽  
Javier Iglesias ◽  
Encarnacion Jimenez ◽  
Enrique Blázquez
Keyword(s):  
Astroglial Cells ◽  
Glycosyl Phosphatidylinositol ◽  
Hydrolysis Of
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