Disease relevance of C00570

• We have purified CMP-NeuAc synthetase from an Escherichia coli O18:K1 cytoplasmic fraction to apparent homogeneity by ion exchange chromatography and affinity chromatography on CDP-ethanolamine linked to agarose [1].
• Cloning and expression of mouse liver phosphatidylserine synthase-1 cDNA. Overexpression in rat hepatoma cells inhibits the CDP-ethanolamine pathway for phosphatidylethanolamine biosynthesis [2].
• CDPcholine and CDPethanolamine prevent the release of free fatty acids during brain ischemia [3].
• Effects of CDPcholine and CDPethanolamine on the alterations in rat brain lipid metabolism induced by global ischemia [4].

High impact information on C00570

• In pulse-chase experiments with CDP-[3H]ethanolamine we show that the GPI phosphoethanolamine is not derived directly from CDP-ethanolamine, but instead from a relatively stable metabolite, such as phosphatidylethanolamine (PE), generated from CDP-ethanolamine in the cell-free system [5].
• Alternatively, PE can be synthesized in the endoplasmic reticulum (ER) from the CDP-ethanolamine pathway [6].
• Taken together, this work demonstrated that the zinc-mediated regulation of ethanolamine kinase and the synthesis of phospholipids via the CDP-ethanolamine branch of the Kennedy pathway were controlled in part by Zap1p [7].
• The amount and activity of a key enzyme of the CDP-ethanolamine pathway for PE synthesis, CTP:phosphoethanolamine cytidylyltransferase, were increased by 35-40 and 100%, respectively, in tissues of Pisd+/- mice, as judged by immunoblotting; PE synthesis from [3H]ethanolamine was correspondingly increased in hepatocytes [8].
• Most of the phosphatidylethanolamine (PE) in mammalian cells is synthesized by two pathways, the CDP-ethanolamine pathway and the phosphatidylserine (PS) decarboxylation pathway, the final steps of which operate at spatially distinct sites, the endoplasmic reticulum and mitochondria, respectively [8].

Biological context of C00570

• PtdEtn is made in hepatocytes by two major pathways, (a) from CDP-ethanolamine on the endoplasmic reticulum and (b) by decarboxylation of phosphatidylserine in mitochondria [9].
• However, CDPethanolamine had no effect on arachidonic acid metabolism in the mince preparation and CMP appeared to stimulate further hydrolysis of choline glycerophopholipids, resulting in increased accumulation of [3H]arachidonic acid and labeled diglycerides [10].
• The enzyme also catalyzes the phosphorylation of ethanolamine, functioning as the initial enzyme of the CDP-ethanolamine pathway as well [11].

Anatomical context of C00570

• Furthermore, the addition of CDP-ethanolamine to microsomes following preincubation with CMP, resulted in a decrease in [3H]alkylacylglycerol with a concomitant increase in [3H]alkenylacylGPE [12].
• Enzyme activities of the CDP-ethanolamine pathway were not significantly different between the two cell lines [13].
• Highly purified rat brain myelin isolated by two different procedures showed appreciable activity for CDP-ethanolamine: 1,2-diacyl-sn-glycerol ethanolaminephosphotransferase (EC 2.7.8.1) [14].
• The activity of PS decarboxylase activity in keratinocyte mitochondria was inhibited by phosphoethanolamine and PE, but not by ethanolamine or CDP-ethanolamine [15].
• The N-methylation of the metabolically specific pool of PE, synthesized from CDP-ethanolamine, is drastically reduced in membranes prepared from choline-grown cells [16].

Associations of C00570 with other chemical compounds

• CTP-phosphoethanolamine cytidylyltransferase (ET) is the enzyme that catalyzes the formation of CDP-ethanolamine in the phosphatidylethanolamine biosynthetic pathway from ethanolamine [17].
• The EPT1 gene product utilized CDP-ethanolamine, -monomethylethanolamine, -dimethylethanolamine, and -choline to significant extents, while the CPT1 gene product manifested relative specificity for CDP-choline and -dimethylethanolamine [18].
• Other acid-soluble intermediates identified by thin layer chromatography were CDP-ethanolamine, dCDP-ethanolamine, and glycerophosphorylethanolamine [19].
• 2. Incubation of hepatocytes in the presence of ethanol significantly alters the incorporation of radiolabel from [14C]-choline and [3H]-ethanolamine into the metabolic intermediates and the final products of the CDP-choline and CDP-ethanolamine pathways [20].
• The incorporation of radioactivity into brain phosphorylethanolamine, cytidine-5'-diphosphate (CDP) ethanolamine and phosphatidylethanolamines was examined and quantitated [21].

Gene context of C00570

• Ethanolamine kinase (ATP:ethanolamine O-phosphotransferase, EC 2.7.1. 82) catalyzes the committed step of phosphatidylethanolamine synthesis via the CDP-ethanolamine pathway [22].
• Moreover, expression of murine PSS2 in McArdle cells did not inhibit PtdEtn synthesis via the CDP-ethanolamine pathway, whereas expression of similar levels of PSS1 activity inhibited this pathway by approx. 50% [23].
• The human choline/ethanolamine phosphotransferase 1 (CEPT1) gene codes for a dual-specificity enzyme that catalyzes the de novo synthesis of the two major phospholipids through the transfer of a phosphobase from CDP-choline or CDP-ethanolamine to DAG to form PC and PE [24].
• Ethanolamine kinase (EKI) is the first committed step in phosphatidylethanolamine (PtdEtn) biosynthesis via the CDP-ethanolamine pathway [25].
• CTP:phosphoethanolamine cytidylyltransferase (ET) is a key regulatory enzyme in the CDP-ethanolamine pathway for phosphatidylethanolamine synthesis [26].

Analytical, diagnostic and therapeutic context of C00570

• Hepatic levels of ethanolamine and phosphoethanolamine were drastically increased after partial hepatectomy, as compared with sham operation, whereas levels of CDP-ethanolamine and microsomal diacylglycerol were not affected [27].
• The contributions of the CDP-ethanolamine and the base exchange pathways were studied by perfusion with [3H]ethanolamine [28].

References