Zhang Z, Zhou Y, Mendelsohn N J, Bauer G S, Strauss A W
Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA.
Biochim Biophys Acta. 1997 Jan 3;1350(1):53-64. doi: 10.1016/s0167-4781(96)00141-8.
Mitochondrial fatty acid oxidation provides most of the energy required for myocardial function after birth. Long chain acyl-CoA dehydrogenase (LCAD) catalyzes the first step in the beta-oxidation spiral. Our objective was to define regulatory elements of the human LCAD gene required for high levels of expression in mature heart and to locate elements suppressing gene expression in the fetus. We characterized the human LCAD gene structure and used in vitro transfection into cardiomyocytes and hepatoma cells of LCAD genomic fragments fused to a reporter gene to examine the effects of putative regulatory elements on transcription. Binding of transcription factors to nuclear hormone receptor consensus DNA binding domains was studied by gel shift experiments. The 200 bp of the human LCAD gene immediately upstream of the transcription initiation site are sufficient to act as a minimal promoter for the gene and provide some tissue-specific positive regulatory elements. The region from -1800 bp to -250 bp contains elements which markedly suppress transcription, including nuclear hormone receptor response elements. The dominant interaction is with the repressor factor, chicken ovalbumin upstream promoter transcription factor. We conclude that the developmental and tissue-specific regulation of the human LCAD gene is mediated, in part, by these nuclear hormone receptor transcription factors.
线粒体脂肪酸氧化为出生后心肌功能提供了大部分所需能量。长链酰基辅酶A脱氢酶（LCAD）催化β-氧化螺旋的第一步。我们的目标是确定人类LCAD基因在成熟心脏中高水平表达所需的调控元件，并定位在胎儿中抑制基因表达的元件。我们对人类LCAD基因结构进行了表征，并将与报告基因融合的LCAD基因组片段体外转染到心肌细胞和肝癌细胞中，以研究推定调控元件对转录的影响。通过凝胶迁移实验研究转录因子与核激素受体共有DNA结合域的结合。人类LCAD基因转录起始位点上游紧邻的200 bp足以作为该基因的最小启动子，并提供一些组织特异性的正调控元件。从-1800 bp到-250 bp的区域包含明显抑制转录的元件，包括核激素受体反应元件。主要的相互作用是与阻遏因子，即鸡卵清蛋白上游启动子转录因子。我们得出结论，人类LCAD基因的发育和组织特异性调控部分是由这些核激素受体转录因子介导的。
