Solute carrier family 25, member 20 (SLC25A20) is a key molecule that transfers acylcarnitine esters in exchange for free carnitine across the mitochondrial membrane in the mitochondrial beta-oxiclation. The peroxisome proliferator-activated receptor alpha (PPAR alpha) is a ligand-activated transcription factor that plays an important role in the regulation of beta-oxidation. We previously established tetracycline-regulated human cell line that can be induced to express PPAR alpha and found that PPAR alpha induces the SLC25A20 expression. In this Study, we analyzed the promoter region of the human slc25a20 gene and showed that PPAR alpha regulates the expression of human SLC25A20 via the peroxisome prolifeFatOF responsive element. (C) 2009 Elsevier Inc. All rights reserved.