MULTIPLE FACTORS INCLUDING THE SMALL NUCLEAR RIBONUCLEOPROTEINS U1 AND U2 ARE NECESSARY FOR PRE-MESSENGER RNA SPLICING INVITRO
MULTIPLE FACTORS INCLUDING THE SMALL NUCLEAR RIBONUCLEOPROTEINS U1 AND U2 ARE NECESSARY FOR PRE-MESSENGER RNA SPLICING INVITRO
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DOI：
10.1016/0092-8674(85)90269-7
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发表时间：
1985-01-01
期刊：
影响因子：
64.5
通讯作者：
MANIATIS, T
中科院分区：
文献类型：
--
作者：
KRAINER, AR;MANIATIS, T
我们已经确定了六个不同的因素所需的前mRNA剪接在体外的选择性失活和互补的研究，并通过分馏程序。剪接因子1（SF 1）对微球菌核酸酶敏感，并且似乎至少由U1和U2 snRNP组成，因为当U1和U2 snRNA的5“末端通过RNA酶H的定点切割被去除时，剪接被抑制。SF 2是一种微球菌核酸酶抗性因子，存在于核提取物中，但在S100提取物中不存在。SF 3是一种可通过适度热处理优先失活的因子。通过使用精胺-琼脂糖和CM-琼脂糖色谱分离核提取物，鉴定了另外两个因子（SF 4A和SF 4 B）。SF 1、SF 2和SF 4 B似乎是在5“剪接位点切割前体mRNA和形成外显子所需的，而SF 3和SF 4A仅是在3”剪接位点切割和外显子连接所需的。
We have identified six distinct factors necessary for pre-mRNA splicing in vitro by selective inactivation and complementation studies, and by fractionation procedures. Splicing factor 1 (SF1) is sensitive to micrococcal nuclease, and appears to consist of at least U1 and U2 snRNPs, since splicing is inhibited when the 5'' termini of U1 and U2 snRNAs are removed by site-directed cleavage with RNAase H. SF2 is a micrococcal nuclease-resistant factor present in the nuclear extract but absent from an S100 extract. SF3 is a factor that can be preferentially inactivated by moderate heat treatment. Two additional factors (SF4A and SF4B) were identified by fractionation of the nuclear extract using spermine-agarose and CM-sepharose chromatography. SF1, SF2, and SF4B appear to be required for cleavage of the pre-mRNA at the 5'' splice site and lariat formation, whereas SF3 and SF4A are only required for cleavage at the 3'' splice site and exon ligation.