Abstract：
:The Delta6-desaturase catalyzes key steps in long-chain polyunsaturated fatty acid biosynthesis. Although the gene coding for this enzyme has been isolated in diverse animal species, the protein structure remains poorly characterized. In this work, rat Delta6-desaturase expressed in COS-7 cells was shown to localize in the endoplasmic reticulum. As the enzyme contains an N-terminal cytochrome b5-like domain, we investigated by site-directed mutagenesis the role of this domain in the enzyme activity. The typical HPGG motif of the cytochrome b5-like domain, and particularly histidine in this motif, is required for the activity of the enzyme, whatever the substrate. Neither endogenous COS-7 cytochrome b5 nor coexpressed rat endoplasmic reticulum cytochrome b5 could rescue the activity of mutated forms of Delta6-desaturase. Moreover, when rat endoplasmic reticulum cytochrome b5 was coexpressed with wild-type desaturase, both proteins interacted and Delta6-desaturase activity was significantly increased. The identified interaction between these proteins is not dependent on the desaturase HPGG motif. These data suggest distinct and essential roles for both the desaturase cytochrome b5-like domain and free endoplasmic reticulum cytochrome b5 for Delta6-desaturase activity.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Guillou H,D'Andrea S,Rioux V,Barnouin R,Dalaine S,Pedrono F,Jan S,Legrand Pdoi
10.1194/jlr.M300339-JLR200keywords:
subject
Has Abstractpub_date
2004-01-01 00:00:00pages
32-40issue
1eissn
0022-2275issn
1539-7262pii
M300339-JLR200journal_volume
45pub_type
杂志文章abstract：:Recent studies suggest: that the epidermis and pilosebaceous epithelium are important sites of de novo sterol synthesis, and that the rate of cutaneous cholesterol synthesis does not change with alterations in circulating sterol levels. Since cutaneous sterols may be important for permeability barrier function, we stu...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1985-04-01 00:00:00
abstract：:We have recently reported that the human apolipoprotein A-I (apoA-I) and apolipoprotein C-III (apoC-III) genes are physically linked and that the presence of a DNA insertion in the apoA-I gene is correlated with apoA-I-apoC-III deficiency in patients with premature atherosclerosis. In addition, the presence of a polym...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1985-04-01 00:00:00
abstract：:The formation of cholic acid from 3alpha, 7alpha, 12alpha-trihydroxy-5beta-cholestan-26-oic acid (THCA) was studied in two normal subjects. [3H]THCA and [14C]cholic acid were administered intravenously by simultaneous injection and the specific activities (percent injected amount/mumol) of [3H]- and [14C]cholic acid w...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1977-09-01 00:00:00
abstract：:Livers from fed or 24-hr fasted male rats were perfused in a recycling system. VLDL labeled with [1-14C]oleate (95% in triglyceride), produced in separate perfusions of livers from fed rats, was added to the medium as a pulse. Uptake of VLDL 14C-labeled triglyceride by livers from fasted rats was less than that from f...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1987-04-01 00:00:00
abstract：:Hepatic steatosis is one of the most common liver disorders in the general population. The main cause of hepatic steatosis is nonalcoholic fatty liver disease (NAFLD), representing the hepatic component of the metabolic syndrome, which is characterized by type 2 diabetes, obesity, and dyslipidemia. Insulin resistance ...
journal_title：Journal of lipid research
pub_type： 杂志文章,评审
doi：10.1194/jlr.R008896
更新日期：2011-04-01 00:00:00
abstract：:The selective and reversible adsorption of bovine low density lipoproteins (LDL) by heparin-Sepharose has been exploited as the critical step in a procedure for the preparative isolation of very low density lipoproteins (VLDL)/chylomicrons, LDL, and high density lipoproteins (HDL) from bovine plasma. Molecular size ex...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1985-06-01 00:00:00
abstract：:Solid-phase extraction (SPE) methods are easy, rapid, and reliable. Their growing popularity is in part due to their operational simplicity and cost reduction in solvents, and partly because they are easier to automate. Sphingolipids are implicated in various cellular events such as growth, differentiation, and apopto...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：2000-09-01 00:00:00
abstract：:Tuberculosis is a major cause of mortality and morbidity due to infectious disease. However, current clinical diagnostic methodologies such as PCR, sputum culture, or smear microscopy are not ideal. Antibody-based assays are a suitable alternative but require specific antibodies against a suitable biomarker. Mycolic a...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.D036137
更新日期：2013-10-01 00:00:00
abstract：:To assess the possible role of altered hepatic processing of free fatty acids in dietary sucrose-induced accumulation of triglyceride in the liver and blood plasma, livers from rats fed commercial laboratory stock and high sucrose diets were perfused both with and without oleic acid substrate. Consumption of the sucro...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1987-10-01 00:00:00
abstract：:Inflammation has been proposed to impair HDL function and reverse cholesterol transport (RCT). We investigated the effects of inflammation mediated by zymosan, a yeast glucan, on multiple steps along the RCT pathway in vivo and ex vivo. Acute inflammation with 70 mg/kg zymosan impaired RCT to plasma, liver, and feces ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M011122
更新日期：2011-05-01 00:00:00
abstract：:Apolipoprotein B (apoB) is a nonexchangeable apolipoprotein. During lipoprotein assembly, it recruits phospholipids and triacylglycerols (TAG) into TAG-rich lipoprotein particles. It remains bound to secreted lipoproteins during lipid metabolism in plasma. The beta1 region (residues 827-1880) of apoB has a high amphip...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M900040-JLR200
更新日期：2009-07-01 00:00:00
abstract：:The effect of electron transport chain redox status on activity of the mitochondrial Ca(2+)-independent phospholipase A2 (iPLA2) has been examined. When oxidizing NAD-linked substrates, the enzyme is not active unless deenergization occurs. Uncoupler, rotenone, antimycin A, and cyanide are equally effective at upregul...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M043307
更新日期：2014-05-01 00:00:00
abstract：:It was reported previously that ceramide-1-phosphate (Cer-1-P) is mitogenic for fibroblasts (Gómez-Muñoz, A., P. A. Duffy, A. Martin, L. O'Brien, H-S. Byun, R. Bittman, and D. N. Brindley. 1995. Mol. Pharmacol. 47: 883-889; Gómez-Muñoz, A., L. M. Frago, L. Alvarez, and I. Varela-Nieto. 1997. Biochem. J. 325: 435-440)....
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M300158-JLR200
更新日期：2004-01-01 00:00:00
abstract：:Mice bearing the Ehrlich ascites tumor were fed diets rich in either coconut oil or sunflower oil. From 20 to 40% less lipid was present in the ascites tumor fluid when the mice were fed the sunflower oil diet. This was associated with a reduction in the amount of very low density lipoproteins (VLDL) and high density ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1978-05-01 00:00:00
abstract：:The diffusion of [2-(14)C]glucose out of liposomes prepared from extracted human erythrocyte lipids was examined. Increased glucose efflux was observed when the lipids were treated with hydrogen peroxide and CuCl(2) before liposome formation, and this phenomenon required both peroxide and metal. Peroxidation of these ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1974-05-01 00:00:00
abstract：:Increased plasma cholesterol is a known risk factor for cardiovascular disease. Lipoprotein particles transport both cholesterol and triglycerides through the blood. It is thought that the size distribution of these particles codetermines cardiovascular disease risk. New types of measurements can determine the concent...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M800354-JLR200
更新日期：2009-12-01 00:00:00
abstract：:Our previous studies have demonstrated the activity of oncostatin M (OM) in stimulating the transcription of the human LDL receptor (LDLR) gene in HepG2 cells through a sterol-independent regulatory mechanism. The current studies were designed to determine whether this in vitro property of OM could be recapitulated in...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M400425-JLR200
更新日期：2005-06-01 00:00:00
abstract：:Conserved lysines and arginines within amino acids 140-150 of apolipoprotein (apo) E are crucial for the interaction between apoE and the low density lipoprotein receptor (LDLR). To explore the roles of amphipathic alpha-helix and basic residue organization in the binding process, we performed site-directed mutagenesi...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：2000-07-01 00:00:00
abstract：:The role of lipid transfer proteins during plasma membrane biogenesis was explored. Developing amphibia embryos were used because during their growth an active plasma membrane biosynthesis occurs together with negligible mitochondrial and endoplasmic reticulum proliferation. Sonicated vesicles, containing 14C-labeled ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1987-01-01 00:00:00
abstract：:Sphingolipids (SLs) have been implicated in numerous important cellular biologies; however, their study has been hindered by the complexities of SL metabolism. Furthermore, enzymes of SL metabolism represent a dynamic and interconnected network in which one metabolite can be transformed into other bioactive SLs throug...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M089714
更新日期：2019-04-01 00:00:00
abstract：:A new method for the purification of apolipoprotein H by affinity chromatography followed by continuous-elution electrophoresis is described. It is both simpler and less complicated than the chromatographic and electrophoretic methods usually used. In addition, apolipoprotein H is isolated in a pure, structurally uncl...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1996-04-01 00:00:00
abstract：:Extracted tissue phospholipid 31P NMR profiles, obtained from individual porcine lenses subjected to two preservation procedures (acetone desiccation and freeze-drying) and a perchloric acid-extraction procedure, were compared to those from freshly excised lens specimens. Each profile yielded quantitative data on 12 l...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1989-03-01 00:00:00
abstract：:The expansion of lipid droplets (LDs) and the differentiation of preadipocytes are two important aspects of mammalian lipid storage. In this study, we examined the role of CDP-diacylglycerol (DAG) synthases (CDSs), encoded by CDS1 and CDS2 genes in mammals, in lipid storage. CDS enzymes catalyze the formation of CDP-D...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M060574
更新日期：2016-05-01 00:00:00
abstract：:Bacterial lipopolysaccharides (LPSs or endotoxins) can bind most proteins of the lipid transfer/LPS-binding protein (LT/LBP) family in host organisms. The LPS-bound LT/LBP proteins then trigger either an LPS-induced proinflammatory cascade or LPS binding to lipoproteins that are involved in endotoxin inactivation and ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.RA120000704
更新日期：2020-12-15 00:00:00
abstract：:A rapid and accurate method is described for the assay of cholesterol ester hydrolase (CEH) activity. Aliquots of the enzyme-substrate incubation mixture are extracted into isopropanol. The free cholesterol concentration in each extract is determined enzymatically using a single aqueous reagent containing cholesterol ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1978-09-01 00:00:00
abstract：:Absorption rates for many biologically important compounds are determined by the relative hydrophobicity of the jejunal microvillus membrane. An estimate of this parameter may be obtained by measuring the incremental change in free energy that occurs when a methylene group partitions into the bilayer form an external ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1989-08-01 00:00:00
abstract：:The aim of this study was to investigate the extent to which inflammation is linked with plasma endothelial lipase (EL) concentrations among healthy sedentary men. Plasma C-reactive protein (CRP) concentrations were measured with a highly sensitive commercial immunoassay, plasma interleukin-6 (IL-6) concentrations wer...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.P600002-JLR200
更新日期：2006-12-01 00:00:00
abstract：:In humans, peroxisomes harbor a complex set of enzymes acting on various lipophilic carboxylic acids, organized in two basic pathways, alpha-oxidation and beta-oxidation; the latter pathway can also handle omega-oxidized compounds. Some oxidation products are crucial to human health (primary bile acids and polyunsatur...
journal_title：Journal of lipid research
pub_type： 杂志文章,评审
doi：10.1194/jlr.R005959
更新日期：2010-10-01 00:00:00
abstract：:Glycosyl hydrolases (GHs) are carbohydrate-active enzymes that hydrolyze a specific β-glycosidic bond in glycoconjugate substrates; β-glucosidases degrade glucosylceramide, a ubiquitous glycosphingolipid. GHs are grouped into structurally similar families that themselves can be grouped into clans. GH1, GH5, and GH30 g...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.R086629
更新日期：2018-12-01 00:00:00
abstract：:Various properties of retinyl ester hydrolysis in the liver and the retinal pigment epithelium (RPE) have been studied, yet the relationship between the retinyl ester hydrolase (REH) activities in these tissues of the same species is not known. In the present study, REH activities in bovine liver and RPE microsomes we...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1996-09-01 00:00:00
