Kim Young Shin, Shin Meong Joo, Yang Dong Jin, Yamaguchi Masamitsu, Park So Young, Yoo Mi Ae
Research Institute of Genetic Engineering, Pusan National University, Busan 609-735, Korea.
Genes Cells. 2007 May;12(5):569-79. doi: 10.1111/j.1365-2443.2007.01075.x.
Adenine nucleotide translocase (ANT) is a crucial component in the maintenance of cellular energy homeostasis, as well as in the formation of the mitochondrial permeability transition pores. However, the molecular mechanisms regulating the expression of the ANT gene are poorly understood. In this study, we have identified three DNA replication-related elements (DRE; 5'-TATCGATA) in the 5'-flanking region of the Drosophila ANT (dANT) gene. Gel-mobility shift analyses revealed that all three of the DREs were recognized by the DRE-binding factor (DREF). The site-directed mutagenesis of these DRE sites induces a considerable reduction in the activity of the dANT gene promoter in vitro. Analyses with transgenic flies harboring a dANT-lacZ fusion gene bearing the wild-type or mutant DRE sites showed that the DRE sites were required for the expression of dANT in vivo. We determined that the over-expression or knockdown of DREF exerts a regulatory effect on the activity of the dANT promoter. In addition, we observed the collapse of mitochondrial membrane potential in the eye imaginal discs in which DREF was over-expressed. These results show that DRE/DREF is a crucial regulator of dANT gene expression, and also suggest the possibility that cross-talk may occur between the DRE/DREF system and mitochondrial functioning.
腺嘌呤核苷酸转位酶（ANT）是维持细胞能量稳态以及线粒体通透性转换孔形成的关键组成部分。然而，调节ANT基因表达的分子机制尚不清楚。在本研究中，我们在果蝇ANT（dANT）基因的5'侧翼区域鉴定出三个与DNA复制相关的元件（DRE；5'-TATCGATA）。凝胶迁移率变动分析表明，所有三个DRE均被DRE结合因子（DREF）识别。这些DRE位点的定点诱变导致体外dANT基因启动子活性显著降低。对携带野生型或突变型DRE位点的dANT-lacZ融合基因的转基因果蝇进行分析表明，DRE位点是体内dANT表达所必需的。我们确定DREF的过表达或敲低对dANT启动子的活性具有调节作用。此外，我们观察到在DREF过表达的眼成虫盘中线粒体膜电位的崩溃。这些结果表明，DRE/DREF是dANT基因表达的关键调节因子，也提示了DRE/DREF系统与线粒体功能之间可能发生相互作用的可能性。
