MOLECULAR-CLONING OF CDNA FOR DOUBLE-STRANDED-RNA ADENOSINE-DEAMINASE, A CANDIDATE ENZYME FOR NUCLEAR-RNA EDITING
MOLECULAR-CLONING OF CDNA FOR DOUBLE-STRANDED-RNA ADENOSINE-DEAMINASE, A CANDIDATE ENZYME FOR NUCLEAR-RNA EDITING
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DOI：
10.1073/pnas.91.24.11457
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发表时间：
1994-11-22
影响因子：
11.1
通讯作者：
NISHIKURA, K
中科院分区：
文献类型：
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作者：
KIM, U;WANG, Y;NISHIKURA, K
我们克隆了编码双链 RNA 腺苷脱氨酶 (DRADA) 的人类 cDNA。 DRADA 是一种普遍存在的核酶，可将双螺旋 RNA 底物中的多种腺苷转化为肌苷，且没有明显的序列特异性。通过昆虫细胞中的重组表达证实了克隆的cDNA编码的蛋白质的A→I转换活性。使用克隆的 DNA 作为分子探针记录了哺乳动物中的序列保守性，并在所有分析的人体组织的 RNA 中检测到了 7 kb 的单个转录物。推导的人DRADA一级结构揭示了二分核定位信号、双链RNA结合蛾的三个重复序列以及其他脱氨酶催化中心保守的序列的存在，包括参与载脂蛋白B RNA编辑的胞苷脱氨酶。这些结构特性与DRADA的酶特征一致，并加强了DRADA对编码谷氨酸门控离子的转录本进行RNA编辑的假设大脑中的通道。
We have cloned human cDNA encoding double-stranded RNA adenosine deaminase (DRADA). DRADA is a ubiquitous nuclear enzyme that converts multiple adenosines to inosines in double helical RNA substrates without apparent sequence specificity. The A --> I conversion activity of the protein encoded by the cloned cDNA was confirmed by recombinant expression in insect cells. Use of the cloned DNA as a molecular probe documented sequence conservation across mammals and detected a single transcript of 7 kb in RNA of all human tissues analyzed. The deduced primary structure of human DRADA revealed a bipartite nuclear localization signal, three repeats of a double-stranded RNA binding moth, and the presence of sequences conserved in the catalytic center of other deaminases, including a cytidine deaminase involved in the RNA editing of apolipoprotein B. These structural properties are consistent with the enzymatic signature of DRADA, and strengthen the hypothesis that DRADA carries out the RNA editing of transcripts encoding glutamate gated ion channels in brain.