Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
Biochemistry. 2010 Sep 28;49(38):8300-6. doi: 10.1021/bi100957h.
The BCL-2 gene encodes a 25 kDa membrane protein that plays critical roles in the control of apoptosis. The regulation of BCL-2 gene expression is highly complex and occurs both transcriptionally and posttranscriptionally. In particular, the 5' upstream region of BCL-2 contains a number of elements that control its expression. We have identified a highly conserved 25-nucleotide G-rich sequence (BCL2Q), with potential to fold into a RNA G-quadruplex structure, located 42 nucleotides upstream of the translation start site of human BCL-2. In this study, we used a series of biophysical experiments to show that the BCL2Q sequence folds into a stable RNA G-quadruplex in vitro, and we conducted functional luciferase reporter-based assays, in a cell-free lysate and in three types of human cell lines, to demonstrate that the BCL2Q sequence modulates protein expression in the context of the 493-nucleotide native 5' untranslated region of BCL-2.
BCL-2 基因编码一种 25kDa 的膜蛋白，在细胞凋亡的调控中起着关键作用。BCL-2 基因表达的调控非常复杂，既可以转录调控，也可以转录后调控。特别是，BCL-2 基因的 5' 上游区域包含了许多控制其表达的元件。我们已经鉴定出一个高度保守的 25 个核苷酸的 G 丰富序列（BCL2Q），它具有折叠成 RNA G-四链体结构的潜力，位于人类 BCL-2 翻译起始位点上游 42 个核苷酸处。在这项研究中，我们使用一系列生物物理实验表明，BCL2Q 序列在体外折叠成稳定的 RNA G-四链体，并且我们在无细胞裂解物和三种类型的人细胞系中进行了基于荧光素酶报告基因的测定，以证明 BCL2Q 序列在 BCL-2 的 493 个核苷酸的天然 5' 非翻译区的背景下调节蛋白质表达。
