Bordonaro M, Nordstrom J L
Department of Biological Sciences, Fordham University, Bronx, NY 10458.
Biochem Biophys Res Commun. 1994 Aug 30;203(1):128-32. doi: 10.1006/bbrc.1994.2158.
A large reduction in the accumulation of mouse beta-globin mRNA occurs when both introns are deleted from its gene. This reduction is ameliorated if a sequence from HSV-1 thymidine kinase (TK), a naturally intronless gene, is inserted into the intronless globin construct. A large reduction in globin mRNA accumulation also occurs when just the terminal 3' splice site region is deleted. This reduction is not ameliorated by the insertion of TK sequence. Different mechanisms therefore must be responsible for the reduced accumulation of mRNA from the intronless and 3' splice site deleted genes. The ability of TK sequence to enhance mRNA accumulation was dependent on its position within the intronless construct. Data are consistent with a model in which pre-mRNAs are co-transcriptionally channelled into intron-dependent or intron-independent metabolic pathways.
当小鼠β-珠蛋白mRNA基因的两个内含子都被缺失时，其积累量会大幅减少。如果将来自单纯疱疹病毒1型胸苷激酶（TK）（一种天然无内含子基因）的序列插入无内含子的珠蛋白构建体中，这种减少会得到改善。当仅缺失末端3'剪接位点区域时，珠蛋白mRNA积累也会大幅减少。这种减少不会因插入TK序列而得到改善。因此，不同的机制必定导致了来自无内含子和3'剪接位点缺失基因的mRNA积累减少。TK序列增强mRNA积累的能力取决于其在无内含子构建体中的位置。数据与一种模型相符，即前体mRNA在转录过程中被引导进入依赖内含子或不依赖内含子的代谢途径。
