A MULTICOMPONENT COMPLEX IS INVOLVED IN THE SPLICING OF MESSENGER-RNA PRECURSORS
A MULTICOMPONENT COMPLEX IS INVOLVED IN THE SPLICING OF MESSENGER-RNA PRECURSORS
复制标题
DOI：
10.1016/s0092-8674(85)80130-6
复制
发表时间：
1985-01-01
期刊：
影响因子：
64.5
通讯作者：
SHARP, PA
中科院分区：
文献类型：
--
作者：
GRABOWSKI, PJ;SEILER, SR;SHARP, PA
被称为剪接体（剪接体）的多组分复合物是 mRNA 前体体外剪接所特有的。该 60S RNA-蛋白质复合物包含来自先前表征的二分剪接中间体的 RNA、5'' 外显子 RNA 和套索插入序列 - 3'' 外显子 RNA，以及一些完整的 455 核苷酸前体 RNA。该复合物含有 snRNP（小核核糖核蛋白），特别是 U1 RNP，如用特异性抗血清进行免疫沉淀所示。 60S 复合物的形成似乎是剪接中早期且重要的步骤，因为 60S 复合物是在第一次共价修饰（前体 RNA 5'' 剪接位点处的切割）之前的反应早期或滞后时间形成的。 60S复合体仅在允许拼接的条件下形成； ATP 和含有真实 5'' 和 3'' 剪接位点的前体 RNA 都是其形成所必需的，而 U1 RNP 特异性抗血清则抑制其形成。 60S复合物中的RNA（主要是前体RNA）被转化为比纯化的前体RNA具有加速动力学和更完全转化的产物。
A multicomponent complex termed spliceosome (splicing body) is unique to the splicing of mRNA precursors in vitro. This 60S RNA-protein complex contains RNA from the previously characterized bipartite splicing intermediate, the 5'' exon RNA, and the lariat intervening sequence-3'' exon RNA, as well as some intact 455 nucleotide precursor RNA. This complex contains snRNP [small nuclear ribonucleoprotein], particularly U1 RNP, as shown by immunoprecipitation with specific antisera. Formation of the 60S complex appears to be an early and essential step in splicing, because the 60S complex forms during the early stage, or lag time, of the reaction before the first covalent modification, cleavage at the 5'' splice site of precursor RNA. The 60S complex forms only under conditions that permit splicing; both ATP and a precursor RNA containing authenic 5'' and 3'' splice sites are required for its formation, while antiserum specific for U1 RNP inhibits its formation. RNA within the 60S complex, predominantly precursor RNA, was chased into products with accelerated kinetics and more complete conversion than purified precursor RNA.