Do sphingoid bases interact with the peroxisome proliferator activated receptor alpha (PPAR-alpha)?
In a search for possible endogenous ligands of nuclear receptors that are activated by peroxisome proliferators (PPARs), a solid phase binding assay was developed employing recombinant mouse PPAR-alpha, containing a myc-epitope, a histidine repeat and a kinase A domain. After in vitro labelling with 32P-gamma-ATP, the binding of purified 32P-PPAR-alpha to a panel of different natural and synthetic lipids, immobilized on silica layers, was evaluated. Autoradiographs of the silica layers revealed binding to two main classes of lipophilic compounds. A first class comprised (poly)unsaturated fatty acids. Compounds belonging to a second class were characterized by the presence of an overall positive charge such as long chain amines, sphingoid bases (sphingenine), and lysoglycosphingolipids (psychosine). PPAR-alpha did not bind to N-acylated sphingoid bases (ceramides) or to sphingenine phosphorylated at the primary hydroxy group (sphingenine-1-phosphate). The binding of PPAR-alpha to sphingoid bases might be of interest given the role of PPAR-alpha and sphingolipids in various cellular processes.
Van Veldhoven
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Departement Moleculaire Celbiologie Afdeling Farmakologie, Katholieke Universiteit Leuven, Campus Gasthuisberg, Herestraat, B-3000, Leuven, Belgium. Vanveldhoven@med.kuleuven.ac.be
Mannaerts
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Declercq
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Baes
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D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002518:Ceramides / Q000378:metabolism; D002855:Chromatography, Thin Layer; D000939:Epitopes; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D006639:Histidine / Q000737:chemistry; D008024:Ligands; D050356:Lipid Metabolism; D051379:Mice; D010770:Phosphotransferases / Q000737:chemistry; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011609:Psychosine / Q000737:chemistry / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013110:Sphingosine / Q000737:chemistry / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
D002518:Ceramides; D000939:Epitopes; D005231:Fatty Acids, Unsaturated; D008024:Ligands; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; C120366:sphingenine-1-phosphate; D011609:Psychosine; D006639:Histidine; D010770:Phosphotransferases; D013110:Sphingosine