RNA mimicry by the fap7 adenylate kinase in ribosome biogenesis.
RNA mimicry by the fap7 adenylate kinase in ribosome biogenesis.
复制标题
核糖体生物发生中FAP7腺苷酸激酶的RNA模拟。
DOI：
10.1371/journal.pbio.1001860
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发表时间：
2014-05
期刊：
影响因子：
9.8
通讯作者：
Leulliot N
中科院分区：
文献类型：
--
作者：
Loc'h J;Blaud M;Réty S;Lebaron S;Deschamps P;Bareille J;Jombart J;Robert-Paganin J;Delbos L;Chardon F;Zhang E;Charenton C;Tollervey D;Leulliot N
与核糖体蛋白结合的核糖体组装因子的结构揭示了一种利用RNA模拟并受ATP水解调节的伴侣功能。在40S和60S核糖体亚基的生物发生过程中，在20S pre-rRNA最终裂解为成熟的18S rRNA之前，40S前颗粒被输出到细胞质中。在参与这一成熟步骤的因素中，Fap7是不寻常的，因为它既与核糖体蛋白Rps14相互作用，又含有腺苷酸激酶活性，这一功能通常与核糖核蛋白组装无关。人类hFap7也通过p53-MDM2途径调节Cajal体组装和细胞周期进程。本文介绍了Fap7-Rps14复合物的功能和结构特征。我们报道，Fap7结合阻断了Rps14的RNA结合表面，相反，Rps14结合抑制了Fap7的腺苷酸激酶活性。此外，结合ADP时，Fap7对Rps14的亲和力更高，而ATP水解会解离该复合物。这些结果表明Fap7以atp依赖的方式通过RNA模拟与Rps14组装成pre-40S颗粒。Fap7结合Rps14导致平台结构域的结构重排，这是pre-rRNA获得切割能力构象所必需的。核糖体是负责所有蛋白质合成的细胞机器。在真核生物中，核糖体的蛋白质和RNA组分的组装极其复杂，涉及200多种非核糖体因子，是成熟复合体中蛋白质数量的三倍。在这些因子中，Fap7蛋白特别有趣，因为它与小亚基核糖体蛋白Rps14相互作用，并表现出腺苷酸激酶活性——一种与调节ATP/ADP水平有关的分子功能，而不是组装蛋白质- rna复合物。结合Rps14 - Fap7复合物的结构和生化分析，我们发现Fap7使用蛋白质侧链模拟RNA接触，使得Rps14与核糖体RNA或Fap7的相互作用具有竞争性和互互性。一旦结合，Rps14就会阻断Fap7的底物结合腔，然后ATP水解会使Fap7 - Rps14复合物分离。同时，Fap7/Rps14复合物形成时，Rps14结合部位的核糖体结构被破坏，这一过程受ATP结合和水解调节。因此，我们的模型是Fap7暂时将Rps14从核糖体中移除，以实现核糖体RNA的构象变化，这是小核糖体亚基最终成熟步骤所需要的。
The structure of a ribosome assembly factor in complex bound to a ribosomal protein uncovers a chaperoning function that uses RNA mimicry and is regulated by ATP hydrolysis. During biogenesis of the 40S and 60S ribosomal subunits, the pre-40S particles are exported to the cytoplasm prior to final cleavage of the 20S pre-rRNA to mature 18S rRNA. Amongst the factors involved in this maturation step, Fap7 is unusual, as it both interacts with ribosomal protein Rps14 and harbors adenylate kinase activity, a function not usually associated with ribonucleoprotein assembly. Human hFap7 also regulates Cajal body assembly and cell cycle progression via the p53–MDM2 pathway. This work presents the functional and structural characterization of the Fap7–Rps14 complex. We report that Fap7 association blocks the RNA binding surface of Rps14 and, conversely, Rps14 binding inhibits adenylate kinase activity of Fap7. In addition, the affinity of Fap7 for Rps14 is higher with bound ADP, whereas ATP hydrolysis dissociates the complex. These results suggest that Fap7 chaperones Rps14 assembly into pre-40S particles via RNA mimicry in an ATP-dependent manner. Incorporation of Rps14 by Fap7 leads to a structural rearrangement of the platform domain necessary for the pre-rRNA to acquire a cleavage competent conformation. Ribosomes are the cellular machines responsible for all protein synthesis. In eukaryotes, the assembly of ribosomes from their protein and RNA components is extremely complicated and involves more than 200 nonribosomal factors—three times the number of proteins in the mature complex. Among these factors, the Fap7 protein is particularly intriguing because it interacts with the small subunit ribosomal protein Rps14 and it exhibits adenylate kinase activity—a molecular function more commonly associated with regulating ATP/ADP levels than assembling protein–RNA complexes. Combining structural and biochemical analysis of the Rps14–Fap7 complex, we show that Fap7 uses protein side chains to mimic RNA contacts, rendering the interaction of Rps14 with ribosomal RNA or with Fap7 competitive and mutually exclusive. Once bound, Rps14 blocks the substrate-binding cavity of Fap7, and ATP hydrolysis will then break the Fap7–Rps14 complex apart. At the same time, the ribosome structure at the location where Rps14 binds is disrupted when the Fap7/Rps14 complex is formed, and this process is regulated by ATP binding and hydrolysis. Our model is thus that Fap7 temporarily removes Rps14 from the ribosome to enable a conformational change of the ribosomal RNA that is needed for the final maturation step of the small ribosomal subunit.
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影响因子：
5.8
作者：
Gouet, P;Courcelle, E;Métoz, F
通讯作者：
Métoz, F
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
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影响因子：
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通讯作者：
Zographos, Spyros E.
DOI：
10.1073/pnas.0909873106
发表时间：
2009-10-20
影响因子：
11.1
作者：
Hoppe, Sven;Bierhoff, Holger;Voit, Renate
通讯作者：
Voit, Renate
影响因子：
6.1
作者：
Evrard, Guillaume;Mareuil, Fabien;Perez, Javier
通讯作者：
Perez, Javier