State Key Laboratory of Crop Stress Adaptation and Improvement, School of life Sciences, Henan University, Kaifeng 475001, China.
Plant Cell Physiol. 2022 Jul 14;63(7):955-966. doi: 10.1093/pcp/pcac060.
As the most abundant RNA modification, pseudouridylation has been shown to play critical roles in Escherichia coli, yeast and humans. However, its function in plants is still unclear. Here, we characterized leaf curly and small 1 (FCS1), which encodes a pseudouridine synthase in Arabidopsis. fcs1 mutants exhibited severe defects in plant growth, such as delayed development and reduced fertility, and were significantly smaller than the wild type at different developmental stages. FCS1 protein is localized in the mitochondrion. The absence of FCS1 significantly reduces pseudouridylation of mitochondrial 26S ribosomal RNA (rRNA) at the U1692 site, which sits in the peptidyl transferase center. This affection of mitochondrial 26S rRNA may lead to the disruption of mitochondrial translation in the fcs1-1 mutant, causing high accumulation of transcripts but low production of proteins. Dysfunctional mitochondria with abnormal structures were also observed in the fcs1-1 mutant. Overall, our results suggest that FCS1-mediated pseudouridylation of mitochondrial 26S rRNA is required for mitochondrial translation, which is critical for maintaining mitochondrial function and plant development.
作为最丰富的 RNA 修饰，假尿嘧啶核苷合成酶已被证明在大肠杆菌、酵母和人类中发挥关键作用。然而，其在植物中的功能尚不清楚。在这里，我们对拟南芥中编码假尿嘧啶核苷合成酶的 FCS1 进行了研究。fcs1 突变体表现出严重的植物生长缺陷，如发育迟缓和繁殖力下降，并且在不同的发育阶段比野生型小得多。FCS1 蛋白定位于线粒体。FCS1 的缺失显著降低了 U1692 位点线粒体 26S rRNA（rRNA）的假尿嘧啶核苷化，该位点位于肽基转移酶中心。这种对线粒体 26S rRNA 的影响可能导致 fcs1-1 突变体中线粒体翻译的中断，导致转录本的大量积累，但蛋白质的产量很低。在 fcs1-1 突变体中还观察到结构异常的功能失调线粒体。总的来说，我们的研究结果表明，FCS1 介导的线粒体 26S rRNA 的假尿嘧啶核苷化对于线粒体翻译是必需的，这对于维持线粒体功能和植物发育至关重要。
