Identification of an erythroid-enriched endoribonuclease activity involved in specific mRNA cleavage
Identification of an erythroid-enriched endoribonuclease activity involved in specific mRNA cleavage
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DOI：
10.1093/emboj/19.2.295
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发表时间：
2000-01-17
期刊：
影响因子：
11.4
通讯作者：
Kiledjian, M
中科院分区：
文献类型：
--
作者：
Wang, ZR;Kiledjian, M
人类 α 珠蛋白 mRNA 的稳定性是由称为 α 复合物的核糖核蛋白复合物赋予的，该复合物通过阻止去腺苷酸化发挥作用。使用我们最近设计的体外发光衰变测定，我们证明α复合物还可以通过保护3'-非翻译区（3'-UTR）免受富含红系的、序列特异性核糖核酸内切酶活性的影响来发挥作用。切割位点被定位到受α复合物保护的区域，并受α复合物的存在调节。在表达外源α-珠蛋白基因的红系细胞中也检测到类似的内切核糖核酸酶裂解产物。靶序列的核苷酸取代使 RNA 对内切核糖核酸酶活性具有抵抗力。将靶序列插入异源 RNA 上可对嵌合 RNA 进行序列特异性切割，证明了该活性的序列特异性。我们得出的结论是，α 复合物通过多方面的方法稳定红细胞中的 α 珠蛋白 mRNA，其中一方面是保护 3'-UTR 免受特定核糖核酸内切酶的切割。
Stability of the human alpha-globin mRNA is conferred by a ribonucleoprotein complex termed the alpha-complex, which acts by impeding deadenylation. Using our recently devised lit vitro decay assay, we demonstrate that the alpha-complex also functions by protecting the 3'-untranslated region (3'-UTR) from an erythroid-enriched, sequence-specific endoribonuclease activity. The cleavage site was mapped to a region protected by the alpha-complex and is regulated by the presence of the alpha-complex. Similar endoribonuclease cleavage products were also detected in erythroid cells expressing an exogenous alpha-globin gene. Nucleotide substitution of the target sequence renders the RNA refractory to the endoribonuclease activity. Insertion of the target sequence onto a heterologous RNA confers sequence-specific cleavage on the chimeric RNA, demonstrating the sequence specificity of this activity. We conclude that the alpha-complex stabilizes the alpha-globin mRNA in erythroid cells by a multifaceted approach, one aspect of which is to protect the 3'-UTR from specific endoribonuclease cleavage.