mRNA and tRNA modification states influence ribosome speed and frame maintenance during poly(lysine) peptide synthesis.
mRNA and tRNA modification states influence ribosome speed and frame maintenance during poly(lysine) peptide synthesis.
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DOI：
10.1016/j.jbc.2022.102039
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发表时间：
2022-06
影响因子：
4.8
通讯作者：
Koutmou, Kristin S.
中科院分区：
文献类型：
--
作者：
Smith, Tyler J.;Tardu, Mehmet;Khatri, Hem Raj;Koutmou, Kristin S.
核糖体速度由多种因素决定，包括底物可用性、细胞条件和产物（肽）形成。翻译在阳离子肽序列的合成过程中减慢，可能影响数千种蛋白质的表达。现有的证据表明，带正电荷的新生肽和带负电荷的核糖体出口通道之间的离子相互作用阻碍翻译。然而，这一假设难以直接检验，因为无法将氨基酸电荷的贡献与细胞中mRNA序列和tRNA的同一性/丰度分离。此外，目前还不清楚翻译系统中对核糖体功能至关重要的其他组分（例如，RNA修饰）影响带正电荷的肽合成的速度和准确性。在这项研究中，我们使用了一个完全重建的大肠杆菌翻译系统，以评估肽电荷，mRNA序列和RNA修饰状态对富含赖氨酸的肽的翻译的影响。用Lys-tRNALys或Val-tRNALys对编码多聚赖氨酸的mRNA进行的翻译反应的比较表明，氨基酸电荷虽然重要，但仅部分解释了这些转录本上的翻译减慢。我们进一步发现，除了肽电荷，mRNA序列和tRNA和mRNA修饰状态影响氨基酸添加的速率和核糖体在多聚赖氨酸肽合成过程中维持框架（而不是进入-2，-1和+1框架）的能力。我们的观察使我们扩展了解释核糖体在多聚赖氨酸肽合成过程中如何减慢的模型，并表明转录后RNA修饰可以为细胞提供一种精确控制核糖体沿mRNA沿着运动的机制。
Ribosome speed is dictated by multiple factors including substrate availability, cellular conditions, and product (peptide) formation. Translation slows during the synthesis of cationic peptide sequences, potentially influencing the expression of thousands of proteins. Available evidence suggests that ionic interactions between positively charged nascent peptides and the negatively charged ribosome exit tunnel impede translation. However, this hypothesis was difficult to test directly because of inability to decouple the contributions of amino acid charge from mRNA sequence and tRNA identity/abundance in cells. Furthermore, it is unclear if other components of the translation system central to ribosome function (e.g., RNA modification) influence the speed and accuracy of positively charged peptide synthesis. In this study, we used a fully reconstituted Escherichia coli translation system to evaluate the effects of peptide charge, mRNA sequence, and RNA modification status on the translation of lysine-rich peptides. Comparison of translation reactions on poly(lysine)-encoding mRNAs conducted with either Lys-tRNALys or Val-tRNALys reveals that that amino acid charge, while important, only partially accounts for slowed translation on these transcripts. We further find that in addition to peptide charge, mRNA sequence and both tRNA and mRNA modification status influence the rates of amino acid addition and the ribosome’s ability to maintain frame (instead of entering the −2, −1, and +1 frames) during poly(lysine) peptide synthesis. Our observations lead us to expand the model for explaining how the ribosome slows during poly(lysine) peptide synthesis and suggest that posttranscriptional RNA modifications can provide cells a mechanism to precisely control ribosome movements along an mRNA.
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DOI：
10.1002/wrna.1586
发表时间：
2020-07
期刊：
Wiley interdisciplinary reviews. RNA
影响因子：
--
作者：
Jones JD;Monroe J;Koutmou KS
通讯作者：
Koutmou KS
影响因子：
16.6
作者：
Hoernes TP;Faserl K;Juen MA;Kremser J;Gasser C;Fuchs E;Shi X;Siewert A;Lindner H;Kreutz C;Micura R;Joseph S;Höbartner C;Westhof E;Hüttenhofer A;Erlacher MD
通讯作者：
Erlacher MD
影响因子：
9.8
作者：
Charneski CA;Hurst LD
通讯作者：
Hurst LD
影响因子：
4.8
作者：
Dimitrova, Lyudmila N.;Kuroha, Kazushige;Inada, Toshifumi
通讯作者：
Inada, Toshifumi
影响因子：
64.5
作者：
Caliskan N;Katunin VI;Belardinelli R;Peske F;Rodnina MV
通讯作者：
Rodnina MV