Crispino J D, Blencowe B J, Sharp P A
Center for Cancer Research, Massachusetts Institute of Technology, Cambridge 02139.
Science. 1994 Sep 23;265(5180):1866-9. doi: 10.1126/science.8091213.
Individual small nuclear ribonucleoproteins (snRNPs) U1, U2, and U4/U6 were removed from nuclear extracts of HeLa cells by antisense affinity depletion. Addition of a highly purified preparation of SR proteins fully restored splicing activity in reactions depleted of U1 snRNP but did not reconstitute splicing in reactions depleted of the other snRNPs. Affinity selection experiments revealed that spliceosomes lacking U1 snRNA formed in the U1 snRNP-depleted reactions reconstituted with SR proteins. Thus, high concentrations of SR proteins facilitate the assembly of precursor messenger RNA (pre-mRNA) into a spliceosome in the absence of interactions with U1 snRNP.
通过反义亲和去除法从HeLa细胞核提取物中去除了单个小核核糖核蛋白（snRNP）U1、U2和U4/U6。添加高度纯化的SR蛋白制剂可完全恢复在去除U1 snRNP的反应中的剪接活性，但不能在去除其他snRNP的反应中重建剪接。亲和选择实验表明，在用SR蛋白重建的U1 snRNP去除反应中形成了缺乏U1 snRNA的剪接体。因此，高浓度的SR蛋白在缺乏与U1 snRNP相互作用的情况下促进前体信使RNA（pre-mRNA）组装成剪接体。
