Open AccessFatty acids and retinoids control lipid metabolism through activation of peroxisome proliferator-activated receptor-retinoid X receptor heterodimers.
Author(s) -
H. J. Keller,
Christine Dreyer,
Jeffrey A. Medin,
Abderrahim Mahfoudi,
Keiko Ozato,
Walter Wahli
Publication year - 1993
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.90.6.2160
Subject(s) - retinoid x receptor , peroxisome proliferator activated receptor , retinoid x receptor alpha , peroxisome , biochemistry , peroxisome proliferator activated receptor alpha , receptor , biology , free fatty acid receptor , nuclear receptor , polyunsaturated fatty acid , retinoic acid , retinoic acid receptor , fatty acid , chemistry , transcription factor , gene
The nuclear hormone receptors called PPARs (peroxisome proliferator-activated receptors alpha, beta, and gamma) regulate the peroxisomal beta-oxidation of fatty acids by induction of the acyl-CoA oxidase gene that encodes the rate-limiting enzyme of the pathway. Gel retardation and cotransfection assays revealed that PPAR alpha heterodimerizes with retinoid X receptor beta (RXR beta; RXR is the receptor for 9-cis-retinoic acid) and that the two receptors cooperate for the activation of the acyl-CoA oxidase gene promoter. The strongest stimulation of this promoter was obtained when both receptors were exposed simultaneously to their cognate activators. Furthermore, we show that natural fatty acids, and especially polyunsaturated fatty acids, activate PPARs as potently as does the hypolipidemic drug Wy 14,643, the most effective activator known so far. Moreover, we discovered that the synthetic arachidonic acid analogue 5,8,11,14-eicosatetraynoic acid is 100 times more effective than Wy 14,643 in the activation of PPAR alpha. In conclusion, our data demonstrate a convergence of the PPAR and RXR signaling pathways in the regulation of the peroxisomal beta-oxidation of fatty acids by fatty acids and retinoids.