Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In animal tissues, NAEs (N-acylethanolamines), including N-arachidonoylethanolamine (anandamide), are primarily formed from their corresponding NAPEs (N-acylphosphatidylethanolamines) by a phosphodiesterase of the PLD (phospholipase D) type (NAPE-PLD). Recently, we cloned cDNAs of NAPE-PLD from mouse, rat and human [Okamoto, Morishita, Tsuboi, Tonai and Ueda (2004) J. Biol. Chem. 279, 5298-5305]. However, it remained unclear whether NAPE-PLD acts on endogenous NAPEs contained in the membrane of living cells. To address this question, we stably transfected two mammalian cell lines (HEK-293 and CHO-K1) with mouse NAPE-PLD cDNA, and investigated the endogenous levels and compositions of NAPEs and NAEs in these cells, compared with mock-transfected cells, with the aid of GC-MS. The overexpression of NAPE-PLD caused a decrease in the total amount of NAPEs by 50-90% with a 1.5-fold increase in the total amount of NAEs, suggesting that the recombinant NAPE-PLD utilizes endogenous NAPE as a substrate in the cell. Since the compositions of NAEs and NAPEs of NAPE-PLD-overexpressing cells and mock-transfected cells were very similar, the enzyme did not appear to discriminate among the N-acyl groups of endogenous NAPEs. These results confirm that overexpressed NAPE-PLD is capable of forming NAEs, including anandamide, in living cells.
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PMID:Mammalian cells stably overexpressing N-acylphosphatidylethanolamine-hydrolysing phospholipase D exhibit significantly decreased levels of N-acylphosphatidylethanolamines. 1576 Mar 4

Monosomy 7 and deletions of 7q are recurring leukemia-associated cytogenetic abnormalities that correlate with adverse outcomes in children and adults. We describe a 2.52-Mb genomic DNA contig that spans a commonly deleted segment of chromosome band 7q22 identified in myeloid malignancies. This interval currently includes 14 genes, 19 predicted genes, and 5 predicted pseudogenes. We have extensively characterized the FBXL13, NAPE-PLD, and SVH genes as candidate myeloid tumor suppressors. FBXL13 encodes a novel F-box protein, SVHis a member of a gene family that contains Armadillo-like repeats, and NAPE-PLD encodes a phospholipase D-type phosphodiesterase. Analysis of a panel of leukemia specimens with monosomy 7 did not reveal mutations in these or in the candidate genes LRRC17, PRO1598, and SRPK2. This fully sequenced and annotated contig provides a resource for candidate myeloid tumor suppressor gene discovery.
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PMID:Isolation and analysis of candidate myeloid tumor suppressor genes from a commonly deleted segment of 7q22. 1582 Mar 12

N-Acyl ethanolamines (NAEs) are a large class of signaling lipids implicated in diverse physiological processes, including nociception, cognition, anxiety, appetite, and inflammation. It has been proposed that NAEs are biosynthesized from their corresponding N-acyl phosphatidylethanolamines (NAPEs) in a single enzymatic step catalyzed by a phospholipase D (NAPE-PLD). The recent generation of NAPE-PLD(-/-) mice has revealed that these animals possess lower brain levels of saturated NAEs but essentially unchanged concentrations of polyunsaturated NAEs, including the endogenous cannabinoid anandamide. These findings suggest the existence of additional enzymatic routes for the production of NAEs in vivo. Here, we report evidence for an alternative pathway for NAE biosynthesis that proceeds through the serine hydrolase-catalyzed double-deacylation of NAPE to generate glycerophospho-NAE, followed by the phosphodiesterase-mediated cleavage of this intermediate to liberate NAE. Furthermore, we describe the functional proteomic isolation and identification of a heretofore uncharacterized enzyme alpha/beta-hydrolase 4 (Abh4) as a lysophospholipase/phospholipase B that selectively hydrolyzes NAPEs and lysoNAPEs. Abh4 accepts lysoNAPEs bearing both saturated and polyunsaturated N-acyl chains as substrates and displays a distribution that closely mirrors lysoNAPE-lipase activity in mouse tissues. These results support the existence of an NAPE-PLD-independent route for NAE biosynthesis and suggest that Abh4 plays a role in this metabolic pathway by acting as a (lyso)NAPE-selective lipase.
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PMID:Endocannabinoid biosynthesis proceeding through glycerophospho-N-acyl ethanolamine and a role for alpha/beta-hydrolase 4 in this pathway. 1681 90

In animal tissues anandamide and other bioactive N-acylethanolamines are principally produced from glycerophospholipids through the transacylation-phosphodiesterase pathway consisting of two enzymatic reactions. The first reaction is the generation of N-acylphosphatidylethanolamine (NAPE) by transferring an acyl group esterified at sn-1 position of glycerophospholipid to the amino group of phosphatidylethanolamine. This reaction is catalyzed by Ca(2+)-dependent N-acyltransferase. The discovery of Ca(2+)-independent N-acyltransferase revealed the existence of plural enzymes which are capable of catalyzing this reaction. The second reaction is the release of N-acylethanolamine from NAPE catalyzed by NAPE-hydrolyzing phospholipase D (NAPE-PLD). The enzyme belongs to the metallo-beta-lactamase family and specifically hydrolyzes NAPEs. Recent studies, including analysis of NAPE-PLD-deficient mice, led to the discovery of NAPE-PLD-independent pathways for the anandamide biosynthesis.
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PMID:Enzymatic formation of anandamide. 1964 6

The biosynthesis of the endocannabinoid anandamide (AEA) and related N-acyl ethanolamine (NAE) lipids is complex and appears to involve multiple pathways, including: (1) direct release of NAEs from N-acyl phosphatidyl ethanolamine (NAPE) precursors by the phosphodiesterase NAPE-PLD, and (2) double O-deacylation of NAPEs followed by phosphodiester bond hydrolysis of the resulting glycero-phospho (GP)-NAEs. We recently identified GDE1 as a GP-NAE phosphodiesterase that may be involved in the second pathway. Here, we report the generation and characterization of GDE1(-/-) mice, which are viable and overtly normal in their cage behavior. Brain homogenates from GDE1(-/-) mice exhibit a near-complete loss of detectable GP-NAE phosphodiesterase activity; however, bulk brain levels of AEA and other NAEs were unaltered in these animals. To address the possibility of compensatory pathways, we generated GDE1(-/-)/NAPE-PLD(-/-) mice. Conversion of NAPE to NAE was virtually undetectable in brain homogenates from these animals as measured under standard assay conditions, but again, bulk changes in brain NAEs were not observed. Interestingly, significant reductions in the accumulation of brain NAEs, including anandamide, were detected in GDE1(-/-)/NAPE-PLD(-/-) mice treated with a fatty acid amide hydrolase (FAAH) inhibitor that blocks NAE degradation. Finally, we determined that primary neurons from GDE1(-/-)/NAPE-PLD(-/-) mice can convert NAPEs to NAEs by a pathway that is not preserved following cell homogenization. In summary, combined inactivation of GDE1 and NAPE-PLD results in partial disruption of NAE biosynthesis, while also pointing to the existence of an additional enzymatic pathway(s) that converts NAPEs to NAEs. Characterization of this pathway should provide clarity on the multifaceted nature of NAE biosynthesis.
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PMID:Characterization of mice lacking candidate N-acyl ethanolamine biosynthetic enzymes provides evidence for multiple pathways that contribute to endocannabinoid production in vivo. 2039 50

Ethanolamides of different long-chain fatty acids constitute a class of endogenous lipid molecules generally called N-acylethanolamines (NAEs). They contain N-arachidonoylethanolamine (anandamide), N-palmitoylethanolamine, and N-oleoylethanolamine, which receive considerable attention because of their actions as an endogenous cannabinoid receptor ligand (endocannabinoid), an anti-inflammatory substance, and an appetite-suppressing substance, respectively. Identification of their biosynthetic routes in animal tissues and molecular characterization of the enzymes involved are essential for better understanding of physiological importance of NAEs as well as development of enzyme inhibitors as possible therapeutic drugs. In the classical "transacylation-phosphodiesterase pathway", NAEs are formed from glycerophospholipids via N-acylphosphatidylethanolamine (NAPE), an unusual derivative of phosphatidylethanolamine with a third acyl chain attached to the amino group, by sequential catalyses by Ca(2+)-dependent N-acyltransferase and NAPE-hydrolyzing phospholipase D. However, recent studies reveal that NAE-generating pathways are more complex than presumed before. In this review article, we will focus on recent findings regarding mammalian enzymes that are involved or might be involved in the biosynthesis of NAEs.
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PMID:Enzymological studies on the biosynthesis of N-acylethanolamines. 2073 84