School of Biosciences, Division of Animal Sciences, University of Nottingham, Sutton Bonington, Leicestershire LE12 5RD, UK.
Biochemistry. 2010 Sep 7;49(35):7625-33. doi: 10.1021/bi100804f.
The 5' end of exon C of the bovine estrogen receptor alpha gene (bov-ESR1) includes a unique G-rich insert, not found in other closely related mammalian genes, which lies close to both a double E-box transcription factor binding site and the site of a single nucleotide (G/A) polymorphism. Biophysical studies, using CD and UV absorbance measurements, show that this 22 base insert leads to the formation of a family of stable G-quadruplex structures which are unaffected by the G/A polymorphism. Multiplex PCR shows that the region including the G-quadruplex is transcribed into RNA, and studies with a synthetic RNA transcript sequence demonstrated formation of a highly stable parallel-folded quadruplex structure. Luciferase reporter constructs demonstrate that the G-rich sequence reduces rates of translation when present in the 5'-UTR of mRNA transcripts. Mutations (GGG to AAA) that destabilize the quadruplex lead to a 15-fold enhancement of translational efficiency, suggesting that a possible biological role of the insert in exon C of the bov-ESR1 is to regulate translation of this exon.
牛雌激素受体α基因（bov-ESR1）外显子 C 的 5'端包含一个独特的富含 G 的插入序列，该序列在其他密切相关的哺乳动物基因中不存在，它靠近双 E 盒转录因子结合位点和单个核苷酸（G/A）多态性位点。使用 CD 和紫外吸收测量的生物物理研究表明，这个 22 个碱基的插入导致形成了一系列稳定的 G-四链体结构，这些结构不受 G/A 多态性的影响。多重 PCR 显示包括 G-四链体的区域被转录成 RNA，并且对合成 RNA 转录本序列的研究表明形成了高度稳定的平行折叠四链体结构。荧光素酶报告基因构建体表明，当富含 G 的序列存在于 mRNA 转录本的 5'UTR 中时，会降低翻译的速度。使四链体不稳定的突变（GGG 突变为 AAA）导致翻译效率提高 15 倍，这表明 bov-ESR1 外显子 C 中的插入序列可能具有调节该外显子翻译的生物学作用。
