Vankan P, McGuigan C, Mattaj I W
EMBL, Heidelberg, FRG.
EMBO J. 1992 Jan;11(1):335-43. doi: 10.1002/j.1460-2075.1992.tb05056.x.
A series of U4 and U6 snRNA mutants was analysed in Xenopus oocytes to determine whether they block splicing complex assembly or splicing itself. All the U4 and U6 mutants found to be inactive in splicing complementation resulted in defects in assembly of either U4/U6 snRNP or of splicing complexes. No mutants were found to separate the entry of U5 and U6 snRNAs into splicing complexes and neither of these RNAs was able to associate with the pre-mRNA in the absence of U4. In the absence of U6 snRNA, however, U4 entered a complex containing pre-mRNA as well as the U1 and U2 snRNAs. U6 nucleotides whose mutation resulted in specific blockage of the second step of splicing in Saccharomyces cerevisiae are shown not to be essential for splicing in the oocyte assay. The results are discussed in terms of the roles of U4 and U6 in the assembly and catalytic steps of the splicing process.
在非洲爪蟾卵母细胞中分析了一系列U4和U6 snRNA突变体，以确定它们是否会阻断剪接复合体组装或剪接本身。所有在剪接互补实验中无活性的U4和U6突变体，都会导致U4/U6 snRNP或剪接复合体组装出现缺陷。未发现有突变体能将U5和U6 snRNA进入剪接复合体的过程分开，并且在没有U4的情况下，这两种RNA都无法与前体mRNA结合。然而，在没有U6 snRNA的情况下，U4进入了一个包含前体mRNA以及U1和U2 snRNA的复合体。在酿酒酵母中，其突变导致剪接第二步特异性阻断的U6核苷酸，在卵母细胞实验中对剪接并非必不可少。根据U4和U6在剪接过程的组装和催化步骤中的作用对结果进行了讨论。
