Functional link between the mammalian exosome and mRNA decapping
Functional link between the mammalian exosome and mRNA decapping
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DOI：
10.1016/s0092-8674(01)00592-x
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发表时间：
2001-12-14
期刊：
影响因子：
64.5
通讯作者：
Kiledjian, M
中科院分区：
文献类型：
--
作者：
Wang, ZR;Kiledjian, M
对哺乳动物信使核糖核酸周转的机制理解仍然不完整。我们证明，3‘到5’外切核糖核酸酶衰变途径是细胞和细胞提取液中的mRNA衰变的主要贡献者。确定了依赖于外切核糖核酸酶的清除剂去皮活性，该活性伴随着mRNA的衰变并水解残余帽。解壳活性与体内外体蛋白的一个子集有关，这意味着一个由外切核酸酶和解壳活性组成的更高级别的降解复合体，它们共同协调mRNA的衰退。这些发现表明，在哺乳动物mRNA去烯化后，降解通过耦合的3‘到5’外切核活性进行，随后通过清道夫去核活性对帽结构进行水解。
Mechanistic understanding of mammalian mRNA turnover remains incomplete. We demonstrate that the 3' to 5' exoribonuclease decay pathway is a major contributor to mRNA decay both in cells and in cell extract. An exoribonuclease-dependent scavenger decapping activity was identified that follows decay of the mRNA and hydrolyzes the residual cap. The decapping activity is associated with a subset:Of the exosome proteins in vivo, implying a higher-order degradation complex consisting of exoribonucleases and a decapping activity, which together coordinate the decay of an mRNA. These findings indicate that following deadenylation of mammal mRNA, degradation proceeds by a coupled 3' to 5' exoribonucleolytic activity and subsequent hydrolysis of the cap structure by a scavenger decapping activity.