Sequence-specific activity of Shiga toxin and other ribosome-inactivating proteins towards different nucleic acid substrates

志贺毒素和其他核糖体失活蛋白对不同核酸底物的序列特异性活性

• 批准号: 452628014
• 负责人: Dr. Samuel Hauf
• 金额: --
• 依托单位: Okinawa Institute of Science and Technology Graduate University (OIST)
• 依托单位国家: 德国
• 项目类别: WBP Fellowship
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/452628014?language=en
• 关键词: Sequence; specific; activity; Shiga; toxin

Shiga toxin, ricin and abrin are among the most potent toxins known. They belong to the class of ribosome-inactivating proteins, or RIPs. These proteins inactivate the places of protein biosynthesis, the ribosomes. To achieve this inactivation, they target a specific site of the ribosomal RNA (rRNA), the so-called sarcin-ricin-loop (SRL). There, they cleave off one specific RNA base. This mechanism is probably the main cause of RIP-toxicity. The effect RIPs have on ribosomes and rRNA has been thoroughly investigated. Some studies also investigated the effect of rRNA sequence and structure on RIP activity, but the effect of all possible mutations of the SRL has not been comprehensively evaluated so far. A reason for could be that the necessary technology was not available. With advances in high-throughput sequencing it has now become feasible to perform such studies. One aim of the proposed project therefore is to comprehensively study the effect of RNA sequence on the activity of RIPs.Besides the well-known effects on rRNA, studies have repeatedly shown activity of RIPs towards other kinds of nucleic acids like ssDNA, dsDNA, and mRNA. Still, there is no knowledge about the sequence specificity of RIPs on these substrates. Any sequence specific effect of RIPs on DNA or mRNA could be of importance for their mechanism of toxicity as well as for the role they play in nature. The general aims of this project are therefore to comprehensively characterize the sequence-specific activity of RIPs on different nucleic acid substrates and to establish the sequencing technology necessary to perform such experiments.

滋贺毒素、蓖麻毒素和相思豆毒素是已知最强的毒素。它们属于核糖体失活蛋白或RIP类。这些蛋白质位于蛋白质生物合成的场所，核糖体。为了实现这种失活，他们靶向核糖体RNA（rRNA）的特定位点，即所谓的sarcin-ricin-loop（SRL）。在那里，它们切断一个特定的RNA碱基。这可能是RIP毒性的主要原因。RIPs对核糖体和rRNA的影响已被彻底研究。一些研究还调查了rRNA序列和结构对RIP活性的影响，但迄今为止尚未全面评估SRL的所有可能突变的影响。一个原因可能是缺乏必要的技术。随着高通量测序的进步，现在进行这样的研究已经变得可行。因此，本课题的目的之一是全面研究RNA序列对RIPs活性的影响。除了已知的对rRNA的影响外，研究反复表明RIPs对其他种类的核酸如ssDNA、dsDNA和mRNA具有活性。然而，目前还没有关于RIP对这些底物的序列特异性的知识。RIPs对DNA或mRNA的任何序列特异性作用对于它们的毒性机制以及它们在自然界中所起的作用都是重要的。因此，本项目的总体目标是全面表征RIPs对不同核酸底物的序列特异性活性，并建立进行此类实验所需的测序技术。