Sun Yuanqiang, Duan Yuange, Gao Peixiang, Liu Chenlu, Jin Kaichun, Dou Shengqian, Tang Wenxiong, Zhang Hong, Lu Jian
State Key Laboratory of Gene Function and Modulation Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing, China.
Eye Institute of Shandong First Medical University, State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Beijing, China.
Elife. 2025 Jun 6;14:RP104074. doi: 10.7554/eLife.104074.
Protein abundance tends to be more evolutionarily conserved than mRNA levels both within and between species, yet the mechanisms underlying this phenomenon remain largely unknown. Upstream open reading frames (uORFs) are widespread -regulatory elements in eukaryotic genomes that regulate translation, but it remains unclear whether and how uORFs contribute to stabilizing protein levels. In this study, we performed ribosome translation simulations on mRNA to quantitatively assess the extent to which uORF translation influences the translational variability of downstream coding sequences (CDSs) across varying contexts. Our simulations revealed that uORF translation dampens CDS translational variability, with buffering capacity increasing in proportion to uORF translation efficiency, length, and number. We then compared the translatomes at different developmental stages of two species, demonstrating that uORFs buffer mRNA translation fluctuations during both evolution and development. Experimentally, deleting a uORF in the () gene-a prominent example of translational buffering-resulted in extensive changes in gene expression and phenotypes in . Additionally, we observed uORF-mediated buffering between primates and within human populations. Together, our results reveal a novel regulatory mechanism by which uORFs stabilize gene translation during development and across evolutionary time.
在物种内部和物种之间，蛋白质丰度往往比mRNA水平在进化上更保守，然而这种现象背后的机制在很大程度上仍然未知。上游开放阅读框（uORF）是真核基因组中广泛存在的调节翻译的元件，但uORF是否以及如何有助于稳定蛋白质水平仍不清楚。在本研究中，我们对mRNA进行了核糖体翻译模拟，以定量评估在不同背景下uORF翻译影响下游编码序列（CDS）翻译变异性的程度。我们的模拟表明，uORF翻译会抑制CDS的翻译变异性，其缓冲能力与uORF的翻译效率、长度和数量成比例增加。然后，我们比较了两个物种不同发育阶段的翻译组，证明uORF在进化和发育过程中缓冲mRNA翻译波动。在实验中，删除（）基因中的一个uORF（翻译缓冲的一个突出例子）导致（）中基因表达和表型发生广泛变化。此外，我们在灵长类动物之间以及人类群体中观察到了uORF介导的缓冲作用。总之，我们的结果揭示了一种新的调节机制，通过这种机制，uORF在发育过程和进化时间内稳定基因翻译。
