Wang Liu, Xu Ya-Peng, Bai Di, Shan Song-Wang, Xie Jie, Li Yan, Wu Wen-Qiang
State Key Laboratory of Crop Stress Adaptation and Improvement, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Henan University, Kaifeng, China.
State Key Laboratory of Crop Stress Adaptation and Improvement, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Henan University, Kaifeng, China.
J Biol Chem. 2022 Aug;298(8):102165. doi: 10.1016/j.jbc.2022.102165. Epub 2022 Jun 20.
RNA G-quadruplexes (rG4s) are noncanonical RNA secondary structures formed by guanine (G)-rich sequences. These complexes play important regulatory roles in both animals and plants through their structural dynamics and are closely related to human diseases and plant growth, development, and adaption. Thus, studying the structural dynamics of rG4s is fundamentally important; however, their folding pathways and their unfolding by specialized helicases are not well understood. In addition, no plant rG4-specialized helicases have been identified. Here, using single-molecule FRET, we experimentally elucidated for the first time the folding pathway and intermediates, including a G-hairpin and G-triplex. In addition, using proteomics screening and microscale thermophoresis, we identified and validated five rG4-specialized helicases in Arabidopsis thaliana. Furthermore, DExH1, the ortholog of the famous human rG4 helicase RHAU/DHX36, stood out for its robust rG4 unwinding ability. Taken together, these results shed light on the structural dynamics of plant rG4s.
RNA G-四链体(rG4s)是由富含鸟嘌呤(G)的序列形成的非经典RNA二级结构。这些复合物通过其结构动力学在动物和植物中发挥重要的调节作用,并且与人类疾病以及植物的生长、发育和适应密切相关。因此,研究rG4s的结构动力学至关重要;然而,它们的折叠途径以及被特定解旋酶解开的过程尚未得到充分理解。此外,尚未鉴定出植物rG4特异性解旋酶。在此,我们使用单分子荧光共振能量转移首次通过实验阐明了折叠途径和中间体,包括一个G-发夹和G-三链体。此外,通过蛋白质组学筛选和微量热泳动,我们在拟南芥中鉴定并验证了五种rG4特异性解旋酶。此外,著名的人类rG4解旋酶RHAU/DHX36的直系同源物DExH1因其强大的rG4解旋能力而脱颖而出。综上所述,这些结果揭示了植物rG4s的结构动力学。