Disease relevance of CEPT1

• AIM: To study the effect of mycophenolate mofetil (Cell Cept) in treating patients with various types of chronic glomerulonephritis and other immune nephropathies [1].

High impact information on CEPT1

• CEPT1 transfers a phosphobase from either CDP-choline or CDP-ethanolamine to diacylglycerol to synthesize both phosphatidylcholine and phosphatidylethanolamine, whereas CPT1 synthesizes phosphatidylcholine exclusively [2].
• Two human genes, CEPT1 and CPT1, code for the total compliment of activities that directly synthesize phosphatidylcholine and phosphatidylethanolamine through the CDP-alcohol pathways [2].
• Thus, substrate channeling of the CDP-choline produced by CTP:phosphocholine cytidylyltransferase alpha to nuclear located CEPT1 is the mechanism by which upregulation of the CDP-choline pathway increases de novo phosphatidylcholine biosynthesis [2].
• We show through immunofluorescence that brefeldin A treatment relocalizes CPT1, but not CEPT1, implying CPT1 is found in the Golgi [2].
• A combination of coimmunofluorescence and subcellular fractionation experiments with various endoplasmic reticulum, Golgi, and nuclear markers confirmed that CPT1 was found in the Golgi and CEPT1 was found in both the endoplasmic reticulum and nuclear membranes [2].

Biological context of CEPT1

• The protein kinase C inhibitor chelerythrine and the human DAG kinase inhibitor R59949 both inhibited CEPT1 activity with IC50 values of 40 microM [3].
• The mixed micelle assay also allowed the lipid activation of CEPT to be measured, and both the cholinephosphotransferase and ethanolaminephosphotransferase activities displayed the unusual property of product activation at 5 mol%, implying that specific lipid activation binding sites exist on CEPT1 [3].
• This pinpointed glycine 156 within the catalytic motif as being responsible for the dual CDP-alcohol specificity of CEPT1, whereas mutations within helix 214-228 allowed for the orientation of transmembrane helices surrounding the catalytic site to be definitively positioned [2].
• The open reading frame predicts a protein (hCEPT1p) of 416 amino acid residues with a molecular mass of 46550 Da containing seven membrane-spanning domains [4].
• In vitro, hCEPT1p displayed broad substrate specificity, utilizing both CDP-choline and CDP-ethanolamine as phosphobase donors to a broad range of diacylglycerols, resulting in the synthesis of both PtdCho and PtdEtn [4].

Anatomical context of CEPT1

• PURPOSE: Our goal was to describe the radiologic features of calcifying fibrous pseudotumor (CEPT) of pleura [5].
• AIM: To test the short term efficacy and safety of an infrared warm compression device (IWCD, Eye Hot, Cept Co, Tokyo, Japan) as treatment for non-inflamed meibomian gland dysfunction (MGD) [6].

Associations of CEPT1 with chemical compounds

• The CEPT1 enzyme displayed an apparent Km of 36 microM for CDP-choline and 4.2 mol% for di-18:1 DAG with a Vmax of 14.3 nmol min(-1) mg(-1) [3].
• 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 [3].
• In vitro assessment of hCPT1 and hCEPT1 derived cholinephosphotransferase activities also revealed differences in diradylglycerol specificities including their capacity to synthesize platelet-activating factor and platelet-activating factor precursor [7].
• Disappearance of measurable mycophenolate mofetil (Cell Cept) in a patient with a renal transplant and an ileostomy [8].
• The rise of CETP activity was significantly related with the plasma steady-state drug levels (r = 0.51, P less than 0.005), thus suggesting that probucol may directly stimulate CEPT synthesis and/or release [9].

Other interactions of CEPT1

• The hCPT1 and human choline/ethanolaminephosphotransferase (hCEPT1) predicted amino acid sequences possessed 60% overall identity and had only one variation in the amino acid residues within the CDP-alcohol phosphotransferase catalytic motif [7].

Analytical, diagnostic and therapeutic context of CEPT1

• Northern blot analysis revealed one hCEPT1 2.3 kb transcript that was ubiquitous and not enriched, with respect to actin, in any particular cell type [4].
• A 69-year-old male heart transplant recipient, being treated with Cell Cept, FK 506 and methylprednisolone had multiple deep brown skin nodules and nodes, on the upper right arm [10].

References