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Nada A Abumrad - One of the best experts on this subject based on the ideXlab platform.
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expression of the cd36 homolog fat in fibroblast cells effects on fatty acid transport
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Azeddine Ibrahimi, Ezzoubir Amri, Zeina Sfeir, Hengameh Magharaie, Paul A Grimaldi, Nada A AbumradAbstract:Abstract An Adipocyte Membrane glycoprotein, (FAT), homologous to human CD36, has been previously implicated in the binding/transport of long-chain fatty acids. It bound reactive derivatives of long-chain fatty acids and binding was specific and associated with significant inhibition of fatty acid uptake. Tissue distribution of the protein and regulation of its expression were also consistent with its postulated role. In this report, we have examined the effects of FAT expression on rates and properties of fatty acid uptake by Ob17PY fibroblasts lacking the protein. Three clones (P21, P22, and P25) were selected based on FAT mRNA and protein levels. Cell surface labeling could be demonstrated with the anti-CD36 antibody FITC-OKM5. In line with this, the major fraction of immunoreactive FAT was associated with the plasma Membrane fraction. Assays of oleate and/or palmitate uptake demonstrated higher rates in the three FAT-expressing clones, compared to cells transfected with the empty vector. Clone P21, which had the highest protein levels on Western blots, exhibited the largest increase in transport rates. Fatty acid uptake in FAT-expressing P21 cells reflected two components, a phloretin-sensitive high-affinity saturable component with a Km of 0.004 microM and a basal phloretin-insensitive component that was a linear function of unbound fatty acid. P21 cells incorporated more exogenous fatty acid into phospholipids, indicating that binding of fatty acids was followed by their transfer into the cell and that both processes were increased by FAT expression. The data support the interpretation that FAT/CD36 functions as a high-affinity Membrane receptor/transporter for long-chain fatty acids.
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cloning of a rat Adipocyte Membrane protein implicated in binding or transport of long chain fatty acids that is induced during preAdipocyte differentiation homology with human cd36
Journal of Biological Chemistry, 1993Co-Authors: Nada A Abumrad, M R Elmaghrabi, Ezzoubir Amri, E Lopez, P A GrimaldiAbstract:Abstract A cDNA for an Adipocyte Membrane protein, implicated in the transport of long-chain fatty acids, was isolated by screening with a synthetic oligonucleotide derived from the amino terminal sequence of the protein. The 88-kDa Adipocyte Membrane protein was previously identified by covalent labeling with N-sulfosuccinimidyl esters of long-chain fatty acids which irreversibly inhibited fatty acid transport by 75% (Harmon, C. M., and Abumrad, N.A. (1993) J. Membr. Biol. 124, 261-268). The cDNA (FAT, 2432 base pairs (bp)) contained 70 bp of 5'-untranslated sequence, an open reading frame encoding a 472-amino acid protein with a predicted molecular mass of 52466, and 940 bp of 3'-untranslated sequence with two polyadenylation signal sequences but with no polyadenylation tail. The deduced protein sequence predicted two transMembrane segments and 10 potential N-linked glycosylation sites. Extensive glycosylation most likely explains why the molecular mass of the isolated protein (88 kDa) is different from that deduced from the cDNA sequence (53 kDa). The sequence of FAT is 85% homologous with that of glycoprotein IV (CD36) identified in human platelets and in lactating mammary epithelium. Consistent with this, a polyclonal antibody against CD36 reacted with Adipocyte plasma Membranes and detected a single band at 88 kDa. Northern blot analysis of RNA obtained from rat adipose tissue and probed with the cDNA identified two major transcripts of 4.8 and 2.9 kilobases which were abundant in heart, intestine, fat, muscle, and testis. The mRNAs were not detectable in cultured adipose cell lines (Ob1771, 3T3F442A) at the fibroblastic stage but were strongly induced during the differentiation process and by treatment of preAdipocytes with dexamethasone, conditions that were also associated with an increase in oleate transport. In contrast, the fibroblastic cell lines 3T3-C2 and L929, which do not differentiate, did not express the mRNAs at all stages of culture. The data suggest that FAT and CD36 belong to a family of proteins that bind/transport long-chain fatty acids or function as regulators of these processes.
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binding of sulfosuccinimidyl fatty acids to Adipocyte Membrane proteins isolation and amino terminal sequence of an 88 kd protein implicated in transport of long chain fatty acids
The Journal of Membrane Biology, 1993Co-Authors: Caroll M Harmon, Nada A AbumradAbstract:We recently reported (Harmon et al., J. Membrane Biol. 124:261–268, 1991) that sulfo-N-succinimidyl derivatives of long-chain fatty acids (SS-FA) specifically inhibited transport of oleate by rat Adipocytes. These compounds bound to an 85–90 kD Membrane protein which was also labeled by another inhibitor of FA transport [3H]DIDS (4,4′-diisothiocyanostilbene-2-2′-sulfonate). These results indicated that the protein was a strong candidate as the transporter for long-chain fatty acids. In this report we determined that the apparent size of the protein is 88 kD and its isoelectric point is 6.9. We used [3H]SS-oleate (SSO), which specifically labels the 88-kD protein, to isolate it from rat Adipocyte plasma Membranes. Identification of 15 amino acids at the N-terminus region revealed strong sequence homology with two previously described Membrane glycoproteins: CD36, a ubiquitous protein originally identified in platelets and PAS IV, a protein that is enriched in the apical Membranes of lipidsecreting mammary cells during lactation. Antibody against PAS IV cross-reacted with the Adipocyte protein. This, together with the N-terminal sequence homology, suggested that the Adipocyte protein belongs to a family of related intrinsic Membrane proteins which include CD36 and PAS IV.
Ezzoubir Amri - One of the best experts on this subject based on the ideXlab platform.
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expression of the cd36 homolog fat in fibroblast cells effects on fatty acid transport
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Azeddine Ibrahimi, Ezzoubir Amri, Zeina Sfeir, Hengameh Magharaie, Paul A Grimaldi, Nada A AbumradAbstract:Abstract An Adipocyte Membrane glycoprotein, (FAT), homologous to human CD36, has been previously implicated in the binding/transport of long-chain fatty acids. It bound reactive derivatives of long-chain fatty acids and binding was specific and associated with significant inhibition of fatty acid uptake. Tissue distribution of the protein and regulation of its expression were also consistent with its postulated role. In this report, we have examined the effects of FAT expression on rates and properties of fatty acid uptake by Ob17PY fibroblasts lacking the protein. Three clones (P21, P22, and P25) were selected based on FAT mRNA and protein levels. Cell surface labeling could be demonstrated with the anti-CD36 antibody FITC-OKM5. In line with this, the major fraction of immunoreactive FAT was associated with the plasma Membrane fraction. Assays of oleate and/or palmitate uptake demonstrated higher rates in the three FAT-expressing clones, compared to cells transfected with the empty vector. Clone P21, which had the highest protein levels on Western blots, exhibited the largest increase in transport rates. Fatty acid uptake in FAT-expressing P21 cells reflected two components, a phloretin-sensitive high-affinity saturable component with a Km of 0.004 microM and a basal phloretin-insensitive component that was a linear function of unbound fatty acid. P21 cells incorporated more exogenous fatty acid into phospholipids, indicating that binding of fatty acids was followed by their transfer into the cell and that both processes were increased by FAT expression. The data support the interpretation that FAT/CD36 functions as a high-affinity Membrane receptor/transporter for long-chain fatty acids.
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cloning of a rat Adipocyte Membrane protein implicated in binding or transport of long chain fatty acids that is induced during preAdipocyte differentiation homology with human cd36
Journal of Biological Chemistry, 1993Co-Authors: Nada A Abumrad, M R Elmaghrabi, Ezzoubir Amri, E Lopez, P A GrimaldiAbstract:Abstract A cDNA for an Adipocyte Membrane protein, implicated in the transport of long-chain fatty acids, was isolated by screening with a synthetic oligonucleotide derived from the amino terminal sequence of the protein. The 88-kDa Adipocyte Membrane protein was previously identified by covalent labeling with N-sulfosuccinimidyl esters of long-chain fatty acids which irreversibly inhibited fatty acid transport by 75% (Harmon, C. M., and Abumrad, N.A. (1993) J. Membr. Biol. 124, 261-268). The cDNA (FAT, 2432 base pairs (bp)) contained 70 bp of 5'-untranslated sequence, an open reading frame encoding a 472-amino acid protein with a predicted molecular mass of 52466, and 940 bp of 3'-untranslated sequence with two polyadenylation signal sequences but with no polyadenylation tail. The deduced protein sequence predicted two transMembrane segments and 10 potential N-linked glycosylation sites. Extensive glycosylation most likely explains why the molecular mass of the isolated protein (88 kDa) is different from that deduced from the cDNA sequence (53 kDa). The sequence of FAT is 85% homologous with that of glycoprotein IV (CD36) identified in human platelets and in lactating mammary epithelium. Consistent with this, a polyclonal antibody against CD36 reacted with Adipocyte plasma Membranes and detected a single band at 88 kDa. Northern blot analysis of RNA obtained from rat adipose tissue and probed with the cDNA identified two major transcripts of 4.8 and 2.9 kilobases which were abundant in heart, intestine, fat, muscle, and testis. The mRNAs were not detectable in cultured adipose cell lines (Ob1771, 3T3F442A) at the fibroblastic stage but were strongly induced during the differentiation process and by treatment of preAdipocytes with dexamethasone, conditions that were also associated with an increase in oleate transport. In contrast, the fibroblastic cell lines 3T3-C2 and L929, which do not differentiate, did not express the mRNAs at all stages of culture. The data suggest that FAT and CD36 belong to a family of proteins that bind/transport long-chain fatty acids or function as regulators of these processes.
P A Grimaldi - One of the best experts on this subject based on the ideXlab platform.
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cloning of a rat Adipocyte Membrane protein implicated in binding or transport of long chain fatty acids that is induced during preAdipocyte differentiation homology with human cd36
Journal of Biological Chemistry, 1993Co-Authors: Nada A Abumrad, M R Elmaghrabi, Ezzoubir Amri, E Lopez, P A GrimaldiAbstract:Abstract A cDNA for an Adipocyte Membrane protein, implicated in the transport of long-chain fatty acids, was isolated by screening with a synthetic oligonucleotide derived from the amino terminal sequence of the protein. The 88-kDa Adipocyte Membrane protein was previously identified by covalent labeling with N-sulfosuccinimidyl esters of long-chain fatty acids which irreversibly inhibited fatty acid transport by 75% (Harmon, C. M., and Abumrad, N.A. (1993) J. Membr. Biol. 124, 261-268). The cDNA (FAT, 2432 base pairs (bp)) contained 70 bp of 5'-untranslated sequence, an open reading frame encoding a 472-amino acid protein with a predicted molecular mass of 52466, and 940 bp of 3'-untranslated sequence with two polyadenylation signal sequences but with no polyadenylation tail. The deduced protein sequence predicted two transMembrane segments and 10 potential N-linked glycosylation sites. Extensive glycosylation most likely explains why the molecular mass of the isolated protein (88 kDa) is different from that deduced from the cDNA sequence (53 kDa). The sequence of FAT is 85% homologous with that of glycoprotein IV (CD36) identified in human platelets and in lactating mammary epithelium. Consistent with this, a polyclonal antibody against CD36 reacted with Adipocyte plasma Membranes and detected a single band at 88 kDa. Northern blot analysis of RNA obtained from rat adipose tissue and probed with the cDNA identified two major transcripts of 4.8 and 2.9 kilobases which were abundant in heart, intestine, fat, muscle, and testis. The mRNAs were not detectable in cultured adipose cell lines (Ob1771, 3T3F442A) at the fibroblastic stage but were strongly induced during the differentiation process and by treatment of preAdipocytes with dexamethasone, conditions that were also associated with an increase in oleate transport. In contrast, the fibroblastic cell lines 3T3-C2 and L929, which do not differentiate, did not express the mRNAs at all stages of culture. The data suggest that FAT and CD36 belong to a family of proteins that bind/transport long-chain fatty acids or function as regulators of these processes.
Zhang Yujing - One of the best experts on this subject based on the ideXlab platform.
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isolation and identification of specific porcine Adipocyte Membrane protein
Chinese journal of veterinary science, 2004Co-Authors: Hao Junyuan, Gao Shizheng, Wang Lei, Zhang YujingAbstract:Porcine Adipocyte Membrane protein and tissue cells Membrane protein were prepared using sucrose gradient centrifugation, and their conformation, molecular weight and relative abundance were analyzed by using SDS-PAGE and scanning densitometer. The results showed that 19 kinds of Membrane protein were found in porcine subcutaneous Adipocytes, 13-24 kinds of Membrane protein were found in heart, liver, spleen, lung, kidney, skeletal muscles and other fat cells, 6 kinds of Membrane protein were found in red cells. Porcine subcutaneous Adipocytes contain 8 kinds of Adipocyte specific Membrane protein, which were identified by using Western-blot, their molecular weight being 110 770,103 910,39 970,31 100,29 420,(25 480,)23 540 and 22 000 respectively. The conformation, molecular weight and relative abundance would be different in porcine Adipocytes and tissue cells Membrane protein.
M Donner - One of the best experts on this subject based on the ideXlab platform.
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Adipocyte and erythrocyte plasma Membrane phospholipid composition and hyperinsulinemia a study in nondiabetic and diabetic obese women
International Journal of Obesity, 2000Co-Authors: Nezha Zeghari, Mohamed Younsi, P Drouin, M Donner, L Meyer, O ZieglerAbstract:BACKGROUND: The cell functions involved in the action of insulin—receptor binding, enzyme and transporter activities—are controlled by Membrane properties. We have previously shown that the fasting plasma insulin (FPI) concentration and the homeostasis model assessment (HOMA) estimate of insulin resistance are associated with the sphingomyelin concentration in the erythrocyte Membranes of obese women. OBJECTIVES: (1) To study the distribution of phospholipid classes in the plasma Membrane and their association with insulin resistance markers in the Adipocyte, an insulin-sensitive cell in obese women. (2) To investigate the influence of diabetes in a small group of obese women treated by diet alone. (3) To compare the distribution of phospholipids in erythrocyte Membranes in a subgroup of obese nondiabetic and diabetic women. SUBJECTS: Subcutaneous fat biopsies were taken from the abdominal region of 19 obese non-diabetic and seven obese type 2 diabetic women. Erythrocyte Membrane assessment was performed in a subgroup of 10 of the 19 obese nondiabetic and in the seven diabetic patients. METHODS: The phospholipid composition of Adipocyte and erythrocyte plasma Membranes was analyzed by high performance liquid chromatography. RESULTS: FPI was positively correlated with the Adipocyte Membrane contents of sphingomyelin (P<0.001), phosphatidylethanolamine (P<0.05), and phosphatidylcholine (P<0.01) in the obese nondiabetic women. Similar correlations were obtained with HOMA. A stepwise multiple regression analysis indicated that sphingomyelin accounted for 45.6 and 43.8% of the variance in FPI and HOMA values as an independent predictor. There was a similar positive independent association between FPI and SM in the erythrocyte Membranes of the studied subgroup. Diabetes per se did not influence the independent association between SM Membrane contents and FPI in both cell types. CONCLUSION: These results suggest a link between Membrane phospholipid composition, especially SM, and hyperinsulinemia in obese women.
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Adipocyte Membrane phospholipids and ppar γ expression in obese women relationship to hyperinsulinemia
American Journal of Physiology-endocrinology and Metabolism, 2000Co-Authors: Nezha Zeghari, Hubert Vidal, Mohamed Younsi, O Ziegler, P Drouin, M DonnerAbstract:We have shown that Membrane sphingomyelin (SM) is an independent predictor of the variance of fasting plasma insulin (FPI) concentrations and the homeostasis model assessment (HOMA) estimate of ins...