0000000000524401
AUTHOR
Vijay Kumar Dasari
The peroxisome proliferator response element (PPRE) present at positions -681/-669 in the rat liver 3-ketoacyl-CoA thiolase B gene functionally interacts differently with PPARalpha and HNF-4.
Although previous data showed that the putative thiolase B PPRE located at -681/-669 bind the PPARalpha-RXRalpha heterodimer in vitro (Kliewer et al. (1992) Nature 358, 771-774), there is no evidence about the functional role of this element. By gel mobility-shift assay, we found an interaction of this PPRE with not only PPARalpha but also with HNF-4. By transfection of cells with the putative PPRE-driven luciferase reporter vector and PPARalpha, we found no significant activation of the luciferase gene expression, in contrast to the case with reporter expression driven by the PPRE of the peroxisomal bifunctional enzyme. On the other hand, HNF-4 activated the luciferase gene expression driv…
Studies on Regulation of the Peroxisomal β-Oxidation at the 3-Ketothiolase Step
The peroxisomal 3-oxoacyl-CoA thiolase (thiolase) is the last enzyme involved in the β-oxidation of fatty acids. The enzyme cleaves long chain fatty acyl-CoA to generate acetyl-CoA and shortened acyl-CoA. The enzyme is nuclear encoded, synthesized in the cytoplasm and transported into peroxisomes. The thiolase B gene is inducible by the peroxisome proliferator compounds, like other genes involved in β-oxidation of fatty acids in peroxisomes.