Guo Wei, Ji Danyang, Kinghorn Andrew B, Chen Feipeng, Pan Yi, Li Xiufeng, Li Qingchuan, Huck Wilhelm T S, Kwok Chun Kit, Shum Ho Cheung
Department of Mechanical Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong 999077, China.
Advanced Biomedical Instrumentation Centre, Hong Kong Science Park, Shatin, New Territories, Hong Kong 999077,China.
J Am Chem Soc. 2023 Feb 1;145(4):2375-2385. doi: 10.1021/jacs.2c11362. Epub 2023 Jan 23.
RNA encodes sequence- and structure-dependent interactions to modulate the assembly and properties of biomolecular condensates. RNA G-quadruplexes (rG4s) formed by guanine-rich sequences can trigger the formation of liquid- or solid-like condensates that are involved in many aberrant phase transitions. However, exactly how rG4 motifs modulate different phase transitions and impart distinct material properties to condensates is unclear. Here, using RNA oligonucleotides and cationic peptides as model systems, we show that RNA-peptide condensates exhibit tunability in material properties over a wide spectrum via interactions arising from rG4 folding/unfolding kinetics. rG4-containing oligonucleotides formed strong pairwise attraction with peptides and tended to form solid-like condensates, while their less-structured non-G4 mutants formed liquid-like droplets. We find that the coupling between rG4 dissociation and RNA-peptide complex coacervation triggers solid-to-liquid transition of condensates prior to the complete unfolding of rG4s. This coupling points to a mechanism that material states of rG4-modulated condensates can be finely tuned from solid-like to liquid-like by the addition of less-structured RNA oligonucleotides, which have weak but dominant binding with peptides. We further show that the tunable material states of condensates can enhance RNA aptamer compartmentalization and RNA cleavage reactions. Our results suggest that condensates with complex properties can emerge from subtle changes in RNA oligonucleotides, contributing ways to treat dysfunctional condensates in diseases and insights into prebiotic compartmentalization.
RNA编码依赖于序列和结构的相互作用，以调节生物分子凝聚物的组装和性质。由富含鸟嘌呤的序列形成的RNA G-四链体（rG4s）可触发液体或固体状凝聚物的形成，这些凝聚物参与许多异常的相变过程。然而，rG4基序究竟如何调节不同的相变并赋予凝聚物独特的材料特性尚不清楚。在这里，我们以RNA寡核苷酸和阳离子肽作为模型系统，表明RNA-肽凝聚物通过rG4折叠/解折叠动力学产生的相互作用，在很宽的范围内展现出材料特性的可调性。含rG4的寡核苷酸与肽形成强烈的成对吸引力，并倾向于形成固体状凝聚物，而其结构较少的非G4突变体则形成液体状液滴。我们发现，rG4解离与RNA-肽复合物凝聚之间的耦合在rG4完全解折叠之前触发凝聚物的固-液转变。这种耦合指向一种机制，即通过添加与肽具有弱但占主导地位结合的结构较少的RNA寡核苷酸，可以将rG4调节的凝聚物的材料状态从固体状精细调节为液体状。我们进一步表明，凝聚物的可调材料状态可以增强RNA适配体的区室化和RNA切割反应。我们的结果表明，具有复杂特性的凝聚物可以从RNA寡核苷酸的细微变化中产生，为治疗疾病中功能失调的凝聚物提供了方法，并为益生元区室化提供了见解。
