THE INTERVENING SEQUENCE OF THE RIBOSOMAL-RNA PRECURSOR IS CONVERTED TO A CIRCULAR RNA IN ISOLATED-NUCLEI OF TETRAHYMENA
THE INTERVENING SEQUENCE OF THE RIBOSOMAL-RNA PRECURSOR IS CONVERTED TO A CIRCULAR RNA IN ISOLATED-NUCLEI OF TETRAHYMENA
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DOI：
10.1016/0092-8674(81)90142-2
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发表时间：
1981-01-01
期刊：
影响因子：
64.5
通讯作者：
CECH, TR
中科院分区：
文献类型：
--
作者：
GRABOWSKI, PJ;ZAUG, AJ;CECH, TR
霸王嗜热菌rRNA基因含有一个插入序列（IVS），它被转录为前体RNA的一部分，随后通过剪接去除。在分离的细胞核中，将IVS作为0.4 kb [RNA酶] RNA切除。发现了一种新的RNA分子，这是一个电泳变异体（EV）的这0.4 kb IVS RNA现在报告。通过Southern杂交、RNA指纹图谱和R-环作图，将EV鉴定为IVS RNA的一种形式。脉冲追踪实验证实，在体外，切除的IVS RNA通过剪接后事件转化为EV。这种转换在39 °时增强。C与30度相比。在这些实验条件下是不可逆的。IVS的EV是环状RNA。这种结构首先是由它的异常电泳迁移率变性相比，非变性凝胶。当在完全变性条件下制备用于EM的EV时，观察到0.4kb环状分子。通过有限的T1 RNase消化将环状形式转化为线性形式。环状RNA在DNA酶、蛋白酶、乙二醛和各种变性剂的处理下存活，这表明它是共价闭合的RNA环。
The T. thermophila rRNA gene contains an intervening sequence (IVS), which is transcribed as part of the precursor RNA and subsequently removed by splicing. The IVS is excised as a 0.4 kb [kilobase] RNA in isolated nuclei. The finding of a novel RNA molecule, which is an electrophoretic variant (EV) of this 0.4 kb IVS RNA is now reported. The EV was identified as a form of the IVS RNA by southern hybridization, RNA fingerprinting and R-loop mapping. A pulse-chase experiment established that in vitro the excised IVS RNA is converted to the EV by a post-splicing event. This conversion is enhanced at 39.degree. C compared to 30.degree. C and is irreversible under these experimental conditions. The EV of the IVS is a circular RNA. This structure was first suggested by its anomalous electrophoretic mobility on denaturing compared to nondenaturing gels. When the EV was prepared for EM under totally denaturing conditions, 0.4 kb circular molecules were observed. The circular form was converted to a linear form by limited T1 RNase digestion. The circular RNA survived treatment with DNase, protease, glyoxal and various denaturants, which suggests that it is a covalently closed RNA circle.