XENOPUS PEROXISOME PROLIFERATOR ACTIVATED RECEPTORS - GENOMIC ORGANIZATION, RESPONSE ELEMENT RECOGNITION, HETERODIMER FORMATION WITH RETINOID-X RECEPTOR AND ACTIVATION BY FATTY-ACIDS
G. Krey et al., XENOPUS PEROXISOME PROLIFERATOR ACTIVATED RECEPTORS - GENOMIC ORGANIZATION, RESPONSE ELEMENT RECOGNITION, HETERODIMER FORMATION WITH RETINOID-X RECEPTOR AND ACTIVATION BY FATTY-ACIDS, Journal of steroid biochemistry and molecular biology, 47(1-6), 1993, pp. 65-73
Peroxisome proliferator activated receptors are ligand activated trans
cription factors belonging to the nuclear hormone receptor superfamily
. Three cDNAs encoding such receptors have been isolated from Xenopus
laevis (xPPAR alpha, beta, and gamma). Furthermore, the gene coding fo
r xPPAR beta has been cloned, thus being the first member of this subf
amily whose genomic organization has been solved. Functionally, xPPAR
alpha as well as its mouse and rat homologs are thought to play an imp
ortant role in lipid metabolism due to their ability to activate trans
cription of a reporter gene through the promoter of the acyl-CoA oxida
se (ACO) gene. ACO catalyzes the rate limiting step in the peroxisomal
beta-oxidation of fatty acids. Activation is achieved by the binding
of xPPAR alpha on a regulatory element (DR1) found in the promoter reg
ion of this gene, xPPAR beta and gamma are also able to recognize the
same type of element and are, as PPAR alpha, able to form heterodimers
with retinoid X receptor. All three xPPARs appear to be activated by
synthetic peroxisome proliferators as well as by naturally occurring f
atty acids, suggesting that a common mode of action exists for all the
members of this subfamily of nuclear hormone receptors.