Acyl-CoA Esters Antagonize the Effects of Ligands on Peroxisome Proliferator-activated Receptor α Conformation, DNA Binding, and Interaction with Co-factors

• Published in: The Journal of biological chemistry 2001-06, Vol.276 (24), p.21410-21416
• Main Authors: Elholm, Morten, Dam, Inge, Jørgensen, Claus, Krogsdam, Anne-M., Holst, Dorte, Kratchmarova, Irina, Göttlicher, Martin, Gustafsson, Jan-Åke, Berge, Rolf, Flatmark, Torgeir, Knudsen, Jens, Mandrup, Susanne, Kristiansen, Karsten
• Format: Article
• Language: English
• Subjects: Acyl Coenzyme A - pharmacology; acyl-CoA esters; Acyl-CoA Oxidase; acyl-CoA-binding protein; Animals; Cell Line; Chromatography, Affinity; Coenzyme A - pharmacology; Dimerization; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - drug effects; DNA-Binding Proteins - metabolism; Genes, Reporter; Glutathione Transferase - genetics; Histone Acetyltransferases; Ligands; Mice; Models, Molecular; NCor protein; Nuclear Receptor Coactivator 1; Oxidoreductases - chemistry; Oxidoreductases - metabolism; palmitoyl-CoA; peroxisome proliferator-activated receptors; Protein Biosynthesis; Protein Conformation; Rats; Receptors, Cytoplasmic and Nuclear - chemistry; Receptors, Cytoplasmic and Nuclear - drug effects; Receptors, Cytoplasmic and Nuclear - metabolism; Receptors, Retinoic Acid - metabolism; Recombinant Proteins - chemistry; Recombinant Proteins - isolation & purification; Recombinant Proteins - metabolism; Retinoid X Receptors; S-hexadecyl-CoA; Spodoptera; Trans-Activators - metabolism; Transcription Factors - chemistry; Transcription Factors - drug effects; Transcription Factors - metabolism; Transcription, Genetic; Transfection
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M101073200

The peroxisome proliferator-activated receptor α (PPARα) is a ligand-activated transcription factor and a key regulator of lipid homeostasis. Numerous fatty acids and eicosanoids serve as ligands and activators for PPARα. Here we demonstrate thatS-hexadecyl-CoA, a nonhydrolyzable palmitoyl-CoA analog, antagonizes the effects of agonists on PPARα conformation and function in vitro. In electrophoretic mobility shift assays, S-hexadecyl-CoA prevented agonist-induced binding of the PPARα-retinoid X receptor α heterodimer to the acyl-CoA oxidase peroxisome proliferator response element. PPARα bound specifically to immobilized palmitoyl-CoA and Wy14643, but not BRL49653, abolished binding. S-Hexadecyl-CoA increased in a dose-dependent and reversible manner the sensitivity of PPARα to chymotrypsin digestion, and theS-hexadecyl-CoA-induced sensitivity required a functional PPARα ligand-binding pocket. S-Hexadecyl-CoA prevented ligand-induced interaction between the co-activator SRC-1 and PPARα but increased recruitment of the nuclear receptor co-repressor NCoR. In cells, the concentration of free acyl-CoA esters is kept in the low nanomolar range due to the buffering effect of high affinity acyl-CoA-binding proteins, especially the acyl-CoA-binding protein. By using PPARα expressed in Sf21 cells for electrophoretic mobility shift assays, we demonstrate that S-hexadecyl-CoA was able to increase the mobility of the PPARα-containing heterodimer even in the presence of a molar excess of acyl-CoA-binding protein, mimicking the conditions found in vivo.