Acyl-CoA Esters Antagonize the Effects of Ligands on Peroxisome Proliferator-activated Receptor a Conformation, DNA Binding, and Interaction with Co-factors
Research output: Contribution to journal › Journal article › Research › peer-review
The peroxisome proliferator-activated receptor alpha (PPARalpha) is a ligand-activated transcription factor and a key regulator of lipid homeostasis. Numerous fatty acids and eicosanoids serve as ligands and activators for PPARalpha. Here we demonstrate that S-hexadecyl-CoA, a nonhydrolyzable palmitoyl-CoA analog, antagonizes the effects of agonists on PPARalpha conformation and function in vitro. In electrophoretic mobility shift assays, S-hexadecyl-CoA prevented agonist-induced binding of the PPARalpha-retinoid X receptor alpha heterodimer to the acyl-CoA oxidase peroxisome proliferator response element. PPARalpha 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 PPARalpha to chymotrypsin digestion, and the S-hexadecyl-CoA-induced sensitivity required a functional PPARalpha ligand-binding pocket. S-Hexadecyl-CoA prevented ligand-induced interaction between the co-activator SRC-1 and PPARalpha 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 PPARalpha expressed in Sf21 cells for electrophoretic mobility shift assays, we demonstrate that S-hexadecyl-CoA was able to increase the mobility of the PPARalpha-containing heterodimer even in the presence of a molar excess of acyl-CoA-binding protein, mimicking the conditions found in vivo.
Original language | English |
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Journal | Journal of Biological Chemistry |
Volume | 276 |
Issue number | 24 |
Pages (from-to) | 21410-6 |
Number of pages | 6 |
ISSN | 0021-9258 |
DOIs | |
Publication status | Published - 2001 |
Externally published | Yes |
Bibliographical note
Keywords: Acyl Coenzyme A; Acyl-CoA Oxidase; Animals; Cell Line; Chromatography, Affinity; Coenzyme A; DNA-Binding Proteins; Dimerization; Genes, Reporter; Glutathione Transferase; Histone Acetyltransferases; Ligands; Mice; Models, Molecular; Oxidoreductases; Protein Biosynthesis; Protein Conformation; Rats; Receptors, Cytoplasmic and Nuclear; Receptors, Retinoic Acid; Recombinant Proteins; Retinoid X Receptors; Spodoptera; Trans-Activators; Transcription Factors; Transcription, Genetic; Transfection
ID: 11255523