Hwang L S, Park J, Gilboa E
Mol Cell Biol. 1984 Nov;4(11):2289-97. doi: 10.1128/mcb.4.11.2289-2297.1984.
Formation of the Moloney murine leukemia virus envelope mRNA involves the removal of a 5,185-base pair-long intron. Deletion analysis of two Moloney murine leukemia virus-derived expression vectors revealed the existence of two short regions within the viral intron which are required for the efficient formation of the spliced RNA species. One region was present upstream from the 3' splice junction, extended at least 85 nucleotides beyond the splice site, and was not more than 165 nucleotides long. As yeast polymerase II introns, the Moloney murine leukemia virus intron contains the sequence 5'-TACTAAC-3' 15 nucleotides upstream from the 3' splice site. A second region located in the middle of the intron, within a 560-nucleotide-long sequence, was also essential for formation of the spliced RNA species. The efficient splicing of the env mRNA in the absence of expression of viral genes raises the possibility that similar mechanisms are used to remove introns of (some) cellular genes.
莫洛尼氏鼠白血病病毒包膜mRNA的形成涉及去除一段5185个碱基对长的内含子。对两个源自莫洛尼氏鼠白血病病毒的表达载体进行缺失分析，揭示了病毒内含子内存在两个短区域，它们是有效形成剪接RNA种类所必需的。一个区域位于3'剪接接头上游，延伸至剪接位点以外至少85个核苷酸，长度不超过165个核苷酸。作为酵母聚合酶II内含子，莫洛尼氏鼠白血病病毒内含子在3'剪接位点上游15个核苷酸处含有序列5'-TACTAAC-3'。位于内含子中间、一段560个核苷酸长序列内的第二个区域，对于剪接RNA种类的形成也是必不可少的。在没有病毒基因表达的情况下env mRNA的有效剪接增加了一种可能性，即类似的机制被用于去除（某些）细胞基因的内含子。
