ASSOCIATION OF U2, U4, U5, AND U6 SMALL NUCLEAR RIBONUCLEOPROTEINS IN A SPLICEOSOME-TYPE COMPLEX IN ABSENCE OF PRECURSOR RNA
ASSOCIATION OF U2, U4, U5, AND U6 SMALL NUCLEAR RIBONUCLEOPROTEINS IN A SPLICEOSOME-TYPE COMPLEX IN ABSENCE OF PRECURSOR RNA
复制标题
DOI：
10.1073/pnas.85.15.5459
复制
发表时间：
1988-08-01
影响因子：
11.1
通讯作者：
SHARP, PA
中科院分区：
文献类型：
--
作者：
KONARSKA, MM;SHARP, PA
小核核糖核蛋白颗粒（snRNP）在mRNA前体的剪接过程中结合形成多snRNP复合物。三种snRNP U4、U 5和U6中的绝大多数存在于单个复合物的核提取物中，而U1和U2 snRNP作为单独的颗粒存在。在体外剪接的最佳条件下，U4-U 5-U6（U4/5/6）复合物解离释放游离snRNP，表明其组分之间的相互作用是动态的。在体外剪接过程中，几种形式的剪接复合物在前体RNA上组装。剪接体B是其中一种形式，含有与前体RNA结合的U2、U4、U 5和U6 snRNP。在高盐浓度下孵育提取物期间，在不存在前体RNA的情况下，这组相同的snRNP有效地缔合。这种U2-U4-U 5-U6（U2/4/5/6）复合物（假剪接体）的形成表明剪接体的基本结构由snRNP-snRNP相互作用指定。
Small nuclear ribonucleoprotein particles (snRNPs) associate to form multi-snRNP complexes during splicing of mRNA precursors. A vast majority of the three snRNPs U4, U5, and U6 are present in a nuclear extract in a single complex, while U1 and U2 snRNPs exist as separate particles. Under conditions optimal for splicing in vitro the U4-U5-U6 (U4/5/6) complex dissociates to release free snRNPs, suggesting that the interactions between its components are dynamic. Several forms of splicing complexes assemble on precursor RNA during splicing in vitro. One of these forms, spliceosome B, contains U2, U4, U5, and U6 snRNPs bound to the precursor RNA. This same set of snRNPs associates efficiently in the absence of precursor RNA during incubation of the extract at high salt concentration. Formation of this U2-U4-U5-U6 (U2/4/5/6) complex, the pseudospliceosome, suggests that the basic structure of the spliceosome is specified by snRNP-snRNP interactions.