Gene expression is prone to burst production, making it a highly noisy process that requires additional controls. Upstream open reading frames (uORFs) are widely present in the 5′ leader sequences of 30–50% of eukaryotic messenger RNAs^1,2,3. The translation of uORFs can repress the translation efficiency of the downstream main coding sequences. Whether the low translation efficiency leads to a different variation, or noise, in gene expression has not been investigated, nor has the direct biological impact of uORF-repressed translation. Here we show that uORFs achieve low but precise protein production in plant cells, possibly by reducing the protein production rate. We also demonstrate that, by buffering a stable TIMING OF CAB EXPRESSION 1 (TOC1) protein production level, uORFs contribute to the robust operation of the plant circadian clock. Our results provide both an action model and the biological impact of uORFs in translational control to mitigate transcriptional noise for precise protein production.

基因表达容易爆发性生产，使其成为一个需要额外控制的高度嘈杂的过程。上游开放阅读框 (uORF) 广泛存在于 30-50% 的真核信使 RNA 的 5' 前导序列中^1,2,3. uORFs 的翻译可以抑制下游主要编码序列的翻译效率。尚未研究低翻译效率是否会导致基因表达中的不同变异或噪音，也没有研究 uORF 抑制翻译的直接生物学影响。在这里，我们表明 uORF 在植物细胞中实现了低但精确的蛋白质生产，可能是通过降低蛋白质生产速率。我们还证明，通过缓冲 CAB 表达 1 (TOC1) 蛋白质生产水平的稳定时间，uORF 有助于植物生物钟的稳健运行。我们的结果提供了 uORF 在翻译控制中的作用模型和生物学影响，以减轻转录噪声以实现精确的蛋白质生产。