Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Saccharomyces cerevisiae CPT1 and EPT1 genes are structural genes encoding distinct sn-1,2-diacylglycerol choline- and ethanolaminephosphotransferases. A haploid cpt1 ept1 double null mutant lacked detectable choline- and ethanolaminephosphotransferase activity but was viable for growth, establishing that these enzymes are nonessential. The activities of the CPT1 and EPT1 gene products were independently studied in membranes prepared from strains mutant in the cognate locus using mixed micellar assays. Both enzymes absolutely required phospholipid cofactors; half-maximal activation was observed at low mole fractions, suggesting that a small number of phospholipid molecules are required. The activities of the CPT1 and EPT1 gene products were compared with respect to dioleoylglycerol dependence, CDP-aminoalcohol specificity, phospholipid activation, and inhibition by CMP. 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. The CPT1 and EPT1 gene products exhibited differing properties with respect to phospholipid activation, but this difference was dependent on the CDP-aminoalcohol substrate. In contrast, the two enzymes could be distinguished on the basis of their dioleoylglycerol dependencies, activation by Mg2+, and CMP inhibition profiles regardless of the CDP-aminoalcohol substrate employed. These studies provide the first definitive kinetic properties of individual choline- and ethanolaminephosphotransferases.
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PMID:sn-1,2-diacylglycerol choline- and ethanolaminephosphotransferases in Saccharomyces cerevisiae. Mixed micellar analysis of the CPT1 and EPT1 gene products. 184 19

The regulation of membrane binding and activity of purified CDP:phosphocholine cytidylyl-transferase (CT) by lipid activators and enzyme dephosphorylation was examined. The binding of CT to membranes was analyzed using sucrose-loaded vesicles (SLVs). Binding to phosphatidylcholine vesicles was not detected even at a lipid:protein ratio of approximately 2000 (1 mM PC). CT bound to vesicles containing anionic lipids with apparent molar partition coefficients between 2 x 10(5) and 2 x 10(6), depending on the vesicle charge. The vesicle binding and activation of CT showed very similar sigmoidal dependencies on the lipid negative charge. In addition, diacylglycerol interacted synergistically with anionic phospholipids to stimulate both binding and activation at lower mole percent anionic lipid. These results demonstrate parallel requirements for binding and activity. Dephosphorylation of CT without destabilization was accomplished using the catalytic subunit of protein phosphatase 1. Dephosphorylated CT required a lower mole percent anionic phospholipid than phosphorylated CT for binding to and activation by SLVs. The combination of 10 mol % diacylglycerol and enzyme dephosphorylation shifted the mole percent phosphatidic acid required for half-maximal activation from 25% to 12%. These results suggest a mechanism whereby large changes in CT activity can result from changes in the phosphorylation state combined with small alterations in the membrane content of diacylglycerol. We propose a mechanism whereby dephosphorylation on the domain adjacent to the membrane binding domain increases the affinity of the latter for a negatively charged membrane surface.
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PMID:Binding of CTP:phosphocholine cytidylyltransferase to lipid vesicles: diacylglycerol and enzyme dephosphorylation increase the affinity for negatively charged membranes. 916 86

CDP-2,3-di-O-geranylgeranyl-sn-glycerol synthase (CDP-archaeol synthase) activity was discovered in the membrane fraction of the methanoarchaeon Methanothermobacter thermoautotrophicus cells. It catalyzed the formation of CDP-2,3-di-O-geranylgeranyl-sn-glycerol from CTP and 2,3-di-O-geranylgeranyl-sn-glycero-1-phosphate (unsaturated archaetidic acid). The identity of the reaction product was confirmed by thin layer chromatography, fast atom bombardment-mass spectroscopy, chemical analysis, and by UV spectroscopy. One mole of the product was formed from approximately 1 mol of each of the reactants. The enzyme showed maximal activity at pH 8.5 and 55 degrees C in the presence of Mg(2+) and K(+) ions. By in vivo pulse labeling of phospholipids with (32)P(i), CDP-archaeol was found to be an intracellular intermediate. A cell-free homogenate of M. thermoautotrophicus, when incubated with l-serine, converted the product of CDP-archaeol synthase reaction to a product with the same chromatographic mobility as archaetidylserine. It was concluded from these results that both CDP-archaeol and CDP-archaeol synthase were involved in cellular phospholipid biosynthesis. Among various synthetic substrate analogs, both enantiomers of unsaturated archaetidic acid possessing geranylgeranyl chains showed similar levels of activity, while archaetidic acid with saturated or monounsaturated isoprenoid or straight chains was a poor substrate, despite having the same stereostructure as the fully active substrate. The ester analogs with geranylgeranioyl chains showed significant activities. These results suggest that the enzyme dose not recognize ether or ester bonds between glycerophosphate and hydrocarbon chains nor the stereostructure of the glycerophosphate backbone but mainly targets substrates with geranylgeranyl chains.
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PMID:CTP:2,3-di-O-geranylgeranyl-sn-glycero-1-phosphate cytidyltransferase in the methanogenic archaeon Methanothermobacter thermoautotrophicus. 1096 Apr 77

Chronic papillomatous dermatitis (CPD) is a stoma site complication due to chronic irritant contact dermatitis. Papillomatosis can also arise in the setting of human papillomavirus (HPV) infection or chronic lymphedema (elephantiasis). Herein, we report the case of a 57-year-old female who presented with a papillomatous growth surrounding a loop ileostomy suspected to be recurrent ovarian serous carcinoma. Excisional biopsy demonstrated nevus sebaceous (NS)-like organoid hyperplasia with koilocytes overlying a dermal scar that exhibited lymphangiectases. Polymerase chain reaction and sequencing for HPV DNA detected HPV 16. In situ hybridization for high-risk HPV DNA showed punctate nuclear pattern in the keratinocytes populating the NS-like hyperplasia indicating integrated HPV 16 DNA. No recurrence has been observed 11 months postexcision. Reports of CPD have documented a spectrum of reactive epidermal hyperplasias including pseudoepitheliomatous, verrucous, papillomatous, syringofibroadenomatous, and rudimentary follicular hyperplasias. HPV DNA has been detected in 3 of 4 CDP cases tested to date and in authentic NS. We postulate that localized lymphedema secondary to scarring coupled with chronic epidermal irritation and inflammation allowed for latent HPV infection to manifest as CPD with NS-like cutaneous hyperplasia.
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PMID:Ileostomy-associated chronic papillomatous dermatitis showing nevus sebaceous-like hyperplasia, HPV 16 infection, and lymphedema: a case report and literature review of ostomy-associated reactive epidermal hyperplasias. 2269 64