Schlor Lisa A, Peußner Maya, Müller Silke, Marx Andreas
Department of Chemistry, University of Konstanz Universitätsstraße 10 78457 Konstanz Germany
Konstanz Research School Chemical Biology, University of Konstanz Universitätsstraße 10 78457 Konstanz Germany.
Chem Sci. 2025 Jan 18;16(7):3313-3322. doi: 10.1039/d4sc06542e. eCollection 2025 Feb 12.
Human RNA ligase 1 (Rlig1) catalyzes the ligation of 5'-phosphate to 3'-hydroxyl ends a conserved three-step mechanism. Rlig1-deficient HEK293 cells exhibit reduced cell viability and RNA integrity under oxidative stress, suggesting Rlig1's role in RNA repair maintenance. Reactive oxygen species (ROS) are linked to various diseases, including neurodegenerative disorders and cancer, where RNA damage has significant effects. This study identifies and characterizes Rlig1 inhibitors to elucidate its role in RNA metabolism. We developed a fluorescence resonance energy transfer (FRET)-based assay to monitor RNA ligation and screened a library of 13 026 bioactive small molecules. SGI-1027 emerged as a promising lead compound, and structure-activity relationship (SAR) studies revealed that the terminal residues play a key role in its inhibitory effect. In total 22 SGI-1027 derivatives were synthesized and tested, providing insights into the structural requirements for effective Rlig1 inhibition. Three derivatives showed low micromolar IC values and minimal cytotoxicity in HEK293 cells under physiological conditions. The combination of Rlig1 inhibition and oxidative stress led to reduced cell viability and compromised RNA integrity, reinforcing Rlig1's role in RNA maintenance. These findings provide a foundation for developing novel therapeutics aimed at targeting RNA maintenance pathways in conditions of dysregulated ROS levels.
人类RNA连接酶1（Rlig1）通过一种保守的三步机制催化5'-磷酸与3'-羟基末端的连接。Rlig1缺陷的HEK293细胞在氧化应激下细胞活力降低，RNA完整性受损，这表明Rlig1在RNA修复维持中发挥作用。活性氧（ROS）与多种疾病相关，包括神经退行性疾病和癌症，在这些疾病中RNA损伤具有显著影响。本研究鉴定并表征了Rlig1抑制剂，以阐明其在RNA代谢中的作用。我们开发了一种基于荧光共振能量转移（FRET）的测定法来监测RNA连接，并筛选了一个包含13026种生物活性小分子的文库。SGI-1027成为一种有前景的先导化合物，结构-活性关系（SAR）研究表明末端残基在其抑制作用中起关键作用。总共合成并测试了22种SGI-1027衍生物，为有效抑制Rlig1的结构要求提供了见解。三种衍生物在生理条件下对HEK293细胞显示出低微摩尔IC值和最小的细胞毒性。抑制Rlig1并结合氧化应激导致细胞活力降低和RNA完整性受损，进一步证实了Rlig1在RNA维持中的作用。这些发现为开发针对ROS水平失调情况下靶向RNA维持途径的新型疗法奠定了基础。
