Wang Wei, Mahboubi Amir, Zhu Shaochun, Hanson Johannes, Mateus André, Niittylä Totte
Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden.
Yazhouwan National Laboratory, Sanya, 572025, Hainan, China.
Nat Commun. 2025 Aug 7;16(1):7301. doi: 10.1038/s41467-025-62652-7.
Eukaryotic ribosome biogenesis proceeds from nucleolus to cytosol assisted by various assembly factors. The process is evolutionarily conserved across eukaryotes but differences between the kingdoms are emerging. Here, we describe how the OPENER (OPNR) protein complex is required for 60S ribosome assembly in the model plant Arabidopsis thaliana. The complex is observed on both nuclear envelope and mitochondria, and contains OPNR, OPENER ASSOCIATED PROTEIN 1 (OAP1), OAP2, Cell Division Cycle 48 D (CDC48D) and Calmodulin-interacting protein 111 (CIP111). Depletion of the OPNR complex components results in reproductive lethality and cytoplasmic retention of assembly factors on 60S ribosomes. Subsequent biochemical analyses and structural modelling suggest that OPNR, OAP1 and OAP2 form a claw-like trimer which grabs the ribosome assembly factor RIBOSOMAL PROTEIN L24C (RPL24C) on the pre-60S ribosome. Our results reveal previously unrecognised subcellular complexity of ribosome biogenesis in plants, and point to mitochondria association as a feature to ensure sufficient translational capacity.
真核生物核糖体的生物合成在各种组装因子的协助下从核仁进行到细胞质。这一过程在真核生物中具有进化保守性，但不同生物界之间的差异正在显现。在这里，我们描述了模型植物拟南芥中60S核糖体组装如何需要OPENER（OPNR）蛋白复合体。该复合体在核膜和线粒体上均有观察到，并且包含OPNR、OPENER相关蛋白1（OAP1）、OAP2、细胞分裂周期48 D（CDC48D）和钙调蛋白相互作用蛋白111（CIP111）。OPNR复合体组分的缺失导致生殖致死以及组装因子在60S核糖体上的细胞质滞留。随后的生化分析和结构建模表明，OPNR、OAP1和OAP2形成一个爪状三聚体，它在60S前体核糖体上抓住核糖体组装因子核糖体蛋白L24C（RPL24C）。我们的结果揭示了植物核糖体生物合成中以前未被认识到的亚细胞复杂性，并指出线粒体关联是确保足够翻译能力的一个特征。
