Isolation, characterization of represser protein in expression of human DLST gene.

本研究分析了人二氢硫酰胺琥珀酰基转移酶基因在表达中的作用。该酶是2-氧-戊二酸脱氢酶复合体的核心成分，在线粒体的能量产生中发挥作用。我们已经分离了DLST基因的基因组DNA，并测定了整个核苷酸序列。对DLST基因启动子调控区的序列分析表明，存在类似CAAT-box的序列，但没有发现类似TATA-box的序列。位于该区域的还有类似糖皮质激素反应元件和cAMP反应元件的序列，以及SPL结合位点。因此，DLST基因是一个典型的看家基因。这种类型的基因群具有多个GC盒，但没有TATA盒，由转录因子SPL或SPL相关蛋白激活。然而，在本研究中，我们发现DLST基因不被SPL或SPL相关蛋白激活。转录位点上游的-35至-12区域是DLST基因转录所必需的。此外，我们还发现第二内含子的a区796到964强烈抑制DLST基因的表达。DLST基因可能受转录激活区-35至-12和转录抑制区796至964的组合调控。

In this study, we analyzed the function in expression of human dihydro lipoamide succinyltransferase gene. The enzyme is a core-component of 2-oxoglutarate dehydrogenase complex and plays a role in energy production in mitrochondria. We have isolated the genomic DNA for the DLST gene and determined the entire nucleotide sequence. Sequence analysis of the promoter-regulatory region of the DLST gene showed the presence of a CAAT-box-like sequence but the presence of a TATA-box-like sequence was not evidenced. Also located in this region were sequences resembling glucocorticoid-responsive and cAMP-responsive elements, and an Spl binding site. Thus, the DLST gene is a typical housekeeping gene. Gene group of this type, possessing multiple GC boxes but no TATA box, is activated by transcription factor Spl or Spl-related proteins. In this study, however, we found that the DLST gene is not activated by Spl or Spl-related proteins. A region-35 to-12 upstream from the transcription site is required for the transcription of the DLST gene. Furthermore, we found that the a region +796 to +964 in the second intron strongly supresses the expression of the DLST gene. The DLST gene may be regulated by the combination of the transcrption-activation region-35 to-12 and of the transcription-supression region +796 to +964.