Aebi M, Hornig H, Padgett R A, Reiser J, Weissmann C
Cell. 1986 Nov 21;47(4):555-65. doi: 10.1016/0092-8674(86)90620-3.
We determined the effect on splicing of 24 point mutations in the 5' and 3' splice region of the large rabbit beta-globin intron. In vitro, 3' AG mutations drastically reduce 5' cleavage and abolish splicing. In vivo, the same mutations elicit efficient splicing at a cryptic, rather than the correct, 3' splice site. In vitro, mutations at all but 2 positions of the consensus 5' splice region impair correct splicing and promote joining of exon 1 to exon 3. In vivo, the same mutations show no effect, except for those converting 5' GT to AT or GA, which cause accumulation of lariat intermediate in vitro and in vivo. We conclude that the 5' GT need not be conserved for 5' cleavage and that it plays an important role in cleavage and exon joining at the 3' splice site.
我们确定了大兔β-珠蛋白内含子5'和3'剪接区域中24个点突变对剪接的影响。在体外，3'AG突变会大幅降低5'切割并消除剪接。在体内，相同的突变会在一个隐蔽的而非正确的3'剪接位点引发高效剪接。在体外，除了共有5'剪接区域的2个位置外，其他位置的突变都会损害正确剪接，并促进外显子1与外显子3的连接。在体内，相同的突变没有影响，除了那些将5'GT转换为AT或GA的突变，它们在体外和体内都会导致套索状中间体的积累。我们得出结论，5'GT对于5'切割并非必需保守，并且它在3'剪接位点的切割和外显子连接中起重要作用。
