School of BioSciences, The University of Melbourne, Victoria, 3010, Australia.
Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia.
Sci Rep. 2021 Jan 28;11(1):2410. doi: 10.1038/s41598-021-81610-z.
Arabidopsis REIL proteins are cytosolic ribosomal 60S-biogenesis factors. After shift to 10 °C, reil mutants deplete and slowly replenish non-translating eukaryotic ribosome complexes of root tissue, while controlling the balance of non-translating 40S- and 60S-subunits. Reil mutations respond by hyper-accumulation of non-translating subunits at steady-state temperature; after cold-shift, a KCl-sensitive 80S sub-fraction remains depleted. We infer that Arabidopsis may buffer fluctuating translation by pre-existing non-translating ribosomes before de novo synthesis meets temperature-induced demands. Reil1 reil2 double mutants accumulate 43S-preinitiation and pre-60S-maturation complexes and alter paralog composition of ribosomal proteins in non-translating complexes. With few exceptions, e.g. RPL3B and RPL24C, these changes are not under transcriptional control. Our study suggests requirement of de novo synthesis of eukaryotic ribosomes for long-term cold acclimation, feedback control of NUC2 and eIF3C2 transcription and links new proteins, AT1G03250, AT5G60530, to plant ribosome biogenesis. We propose that Arabidopsis requires biosynthesis of specialized ribosomes for cold acclimation.
拟南芥 REIL 蛋白是细胞质核糖体 60S 生物发生因子。在转移到 10°C 后，reil 突变体耗尽并缓慢补充根组织中无翻译的真核核糖体复合物，同时控制非翻译的 40S 和 60S 亚基的平衡。在稳态温度下，reil 突变体通过非翻译亚基的过度积累做出反应；冷休克后，KCl 敏感的 80S 亚基仍被耗尽。我们推断，拟南芥可能通过在从头合成满足温度诱导的需求之前预先存在的非翻译核糖体来缓冲翻译的波动。Reil1 reil2 双突变体积累 43S-起始前和前 60S-成熟复合物，并改变非翻译复合物中核糖体蛋白的同工基因组成。除了少数例外，例如 RPL3B 和 RPL24C，这些变化不受转录控制。我们的研究表明，真核核糖体的从头合成是长期低温适应所必需的，NUC2 和 eIF3C2 转录的反馈控制以及新的蛋白质 AT1G03250、AT5G60530 与植物核糖体生物发生有关。我们提出，拟南芥需要合成专门的核糖体来适应寒冷。
