Patzelt E, Thalmann E, Hartmuth K, Blaas D, Kuechler E
Nucleic Acids Res. 1987 Feb 25;15(4):1387-99. doi: 10.1093/nar/15.4.1387.
To study the influence of the ubiquitous cap structure of nuclear pre-mRNAs on the assembly of a functional splicing complex, the in vitro splicing of a truncated human metallothionein pre-mRNA was examined in the presence of the cap analogue m7GTP. Significant inhibition of splicing was observed at a concentration as low as 5 microM m7GTP. Analysis of the splicing reaction on glycerol density gradients showed two complexes sedimenting at 45S and 22S. When the reaction was carried out in presence of m7GTP a marked decrease of the material sedimenting at 45S, representing the active splicing complex, was observed. When capped pre-mRNA was replaced by uncapped pre-mRNA, complex formation was significantly reduced. These data indicate that the cap structure plays an important yet unknown role in the assembly of spliceosomes.
为了研究核内前体mRNA普遍存在的帽结构对功能性剪接复合体组装的影响，在帽类似物m7GTP存在的情况下，检测了截短的人金属硫蛋白前体mRNA的体外剪接。在低至5微摩尔的m7GTP浓度下就观察到了剪接的显著抑制。对甘油密度梯度上的剪接反应分析显示有两种复合体分别沉降在45S和22S处。当反应在m7GTP存在的情况下进行时，观察到沉降在45S处代表活性剪接复合体的物质显著减少。当有帽前体mRNA被无帽前体mRNA取代时，复合体的形成显著减少。这些数据表明帽结构在剪接体的组装中起着重要但未知的作用。
