Stark J M, Bazett-Jones D P, Herfort M, Roth M B
Division of Basic Sciences and Molecular and Cellular Biology Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98104, USA.
Proc Natl Acad Sci U S A. 1998 Mar 3;95(5):2163-8. doi: 10.1073/pnas.95.5.2163.
We have developed a defined system to characterize the role of SR proteins and exonic enhancers in directly promoting splice-site interactions across an intron. Using RNA affinity chromatography, we find that SR proteins alone are sufficient to promote the specific association of the enhancer-containing exon 5 with the adjoining exon 6 from avian cardiac troponin-T. Direct visualization of this exon/exon association by electron spectroscopic imaging shows it to be highly specific. Furthermore, using in vivo characterized mutants of exon 5, we also show that this exon/exon association depends on the splicing enhancer within exon 5. These results suggest a model by which SR proteins may function through exonic enhancers to directly promote exon bridging.
我们已经开发出一种特定系统，用于表征SR蛋白和外显子增强子在直接促进内含子上剪接位点相互作用中的作用。通过RNA亲和色谱法，我们发现单独的SR蛋白足以促进含增强子的外显子5与来自禽心肌肌钙蛋白T的相邻外显子6的特异性结合。通过电子光谱成像对这种外显子/外显子结合进行直接观察，结果表明其具有高度特异性。此外，利用体内表征的外显子5突变体，我们还表明这种外显子/外显子结合依赖于外显子5内的剪接增强子。这些结果提示了一种模型，即SR蛋白可能通过外显子增强子发挥作用，直接促进外显子桥接。
