Elucidation of the assembly events required for the recruitment of Utp20, Imp4 and Bms1 onto nascent pre-ribosomes.
Elucidation of the assembly events required for the recruitment of Utp20, Imp4 and Bms1 onto nascent pre-ribosomes.
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DOI：
10.1093/nar/gkr508
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发表时间：
2011-10
影响因子：
14.9
通讯作者：
Dosil M
中科院分区：
文献类型：
--
作者：
Pérez-Fernández J;Martín-Marcos P;Dosil M
90 S前核糖体，也称为小亚基（SSU）加工体，是从前体rRNA产生18 S rRNA所需的大的多亚基颗粒。最近，它已被证明，这种颗粒的形成需要的初始关联的tUTP亚基与新生的前RNA，随后，结合Rrp 5/UTP-C和U3 snoRNP/UTP-B亚基在两个独立的装配分支。然而，其他90 S前核糖体组件的组装模式仍然不清楚。在这项研究中，我们已经调查了组装的三个蛋白质（Utp 20，Imp 4和Bms 1）以前被认为是潜在的成核因子的90 S颗粒。在这里，我们证明了这三种蛋白质加载到前rRNA上独立于Rrp 5/UTP-C发生，而是发生在tUTP和U3/UTP-B亚复合物的下游。我们还表明，Bms 1和Utp 20所需的一个子集的蛋白质新生前核糖体的招聘。最后，我们表明，通过二级步骤相关联的蛋白质条件的稳定性，在部分组装前核糖体的两个组装分支。这些结果提供了有关90 S颗粒组分之间的功能关系以及它们逐步掺入初级前体rRNA所需的事件的新信息。
The 90S pre-ribosome, also known as the small subunit (SSU) processome, is a large multisubunit particle required for the production of the 18S rRNA from a pre-rRNA precursor. Recently, it has been shown that the formation of this particle entails the initial association of the tUTP subunit with the nascent pre-RNA and, subsequently, the binding of Rrp5/UTP-C and U3 snoRNP/UTP-B subunits in two independent assembly branches. However, the mode of assembly of other 90S pre-ribosome components remains obscure as yet. In this study, we have investigated the assembly of three proteins (Utp20, Imp4 and Bms1) previously regarded as potential nucleating factors of the 90S particle. Here, we demonstrate that the loading of those three proteins onto the pre-rRNA takes place independently of Rrp5/UTP-C and, instead, occurs downstream of the tUTP and U3/UTP-B subcomplexes. We also demonstrate that Bms1 and Utp20 are required for the recruitment of a subset of proteins to nascent pre-ribosomes. Finally, we show that proteins associated through secondary steps condition the stability of the two assembly branches in partially assembled pre-ribosomes. These results provide new information about the functional relationships among 90S particle components and the events that are required for their stepwise incorporation onto the primary pre-rRNA.
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影响因子：
4.5
作者：
Dez, Christophe;Dlakic, Mensur;Tollervey, David
通讯作者：
Tollervey, David
影响因子：
14.9
作者：
Granneman, S;Gallagher, JEG;Pruijn, GJM
通讯作者：
Pruijn, GJM
影响因子：
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作者：
Bax, R;Vos, HR;Vos, JC
通讯作者：
Vos, JC
影响因子：
11.4
作者：
Billy, E;Wegierski, T;Filipowicz, W
通讯作者：
Filipowicz, W
影响因子：
16
作者：
Grandi, P;Rybin, V;Hurt, E
通讯作者：
Hurt, E