Hertel K J, Maniatis T
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Mol Cell. 1998 Feb;1(3):449-55. doi: 10.1016/s1097-2765(00)80045-3.
Splicing enhancers are RNA sequences consisting of one or more binding sites (enhancer elements) for specific serine/arginine (SR)-rich proteins. When associated with these elements, SR proteins activate splicing by recruiting the splicing machinery to the adjacent intron through protein-protein interactions. Here, we show that the rate and efficiency of splicing increases linearly, rather than synergistically, as the number of identical or nonidentical enhancer elements present on pre-mRNA is increased. We conclude that only one splicing enhancer complex at a time is capable of interacting with the constitutive splicing machinery. Thus, the function of multisite enhancer elements to increase the probability of an interaction between the enhancer complex and the splicing machinery rather than to promote functional synergy.
剪接增强子是由一个或多个特定富含丝氨酸/精氨酸（SR）蛋白的结合位点（增强子元件）组成的RNA序列。当与这些元件结合时，SR蛋白通过蛋白质-蛋白质相互作用将剪接机制招募到相邻内含子，从而激活剪接。在此，我们表明，随着前体mRNA上存在的相同或不同增强子元件数量的增加，剪接的速率和效率呈线性增加，而非协同增加。我们得出结论，一次只有一个剪接增强子复合体能够与组成型剪接机制相互作用。因此，多位点增强子元件的功能是增加增强子复合体与剪接机制之间相互作用的概率，而非促进功能协同作用。
