Mechanisms of transcription termination

了解基因表达的分子机制对于智能操纵有害和有用的生物、开发新的抗菌和抗真菌药物、抗击疾病以及了解生命的出现和进化是至关重要的。在所有生物中，基因表达的第一步是由高度保守的多亚基RNA聚合酶(RNAP)完成的。终止是转录的一个重要步骤，确保RNAP的循环和相邻基因的正确表达。然而，终止的机制仍然不太清楚。最近，我们发现了一个很好的场景，由RNA聚合酶III终止，它在真核细胞中转录许多必要的基因。我们发现了与细菌终止的相似之处，这表明这一基本机制在数十亿年前就出现了，在生命的三个领域分化之前。这项研究启发我们研究了真核细胞中合成大部分RNA的RNA聚合酶I和在生命的第三个领域发挥作用的古生菌RNAP终止的机制。RNA聚合酶I的故障与癌症、阿尔茨海默氏症和其他疾病有关。古生菌是生态学和生物技术中的重要参与者，也是人类和反刍动物肠道的栖息地。因此，除了基本的重要性外，拟议的研究还可能对医学和环境研究、农业和生物技术产生影响。此外，正如我们对RNA聚合酶III的发现所表明的那样，这项研究可能揭示这些RNA聚合酶的新的和/或独特的特征，并提高对多亚基RNAP功能机制之间的进化关系的理解。实现这些目标所需的广泛技术是我们实验室多年来独特积累的，例如使我们能够破译RNA聚合酶III的终止机制，描述参与调节HIV-1发展的机制，并揭示抗生素Tagetitoxx的作用模式。这项拟议的研究将增加这些技术，并将为研究基因表达的第一步以及设计和测试新药提供新的工具。

Understanding the molecular mechanisms governing the expression of genes is an essential part of developing strategies for intelligent manipulation of harmful and useful organisms, development of new antimicrobial and antifungal agents, fighting diseases, and, importantly, for understanding emergence and evolution of Life.In all living organisms the first step of gene expression is accomplished by highly conserved multi-subunit RNA polymerases (RNAPs). Termination is an essential step of transcription that ensures recycling of RNAP and proper expression of neighbouring genes. However, the mechanisms of termination remain poorly understood.Recently we discovered an elegant scenario of termination by RNA polymerase III, which transcribes many essential genes in eukaryotic cell. We discovered analogies with bacterial termination, which suggest that this fundamental mechanism have emerged billions years ago, before divergence of three domains of life. This research inspired us to investigate the mechanisms of termination by RNA polymerase I, which synthesises most of RNA in eukaryotic cell, and Archaeal RNAP, which functions in the third, much understudied, domain of life. Malfunctions in RNA polymerase I is linked with diseases such as cancer, Alzheimer's and others. Archaea are important players in ecology and biotechnology, as well as inhabit humans and ruminant's guts. Therefore besides fundamental importance, the proposed study may have an impact on medical and environmental research, agriculture and biotechnology. Also, as suggested by our findings with RNA polymerase III, the study may reveal new and/or unique features of these RNA polymerases as well as improve understanding of evolutionary relations among the mechanisms of multi-subunit RNAPs' functioning. The wide range of techniques required to achieve these aims have uniquely accumulated through years in our lab, and for example allowed us to decipher mechanism of termination by RNA polymerase III, describe a mechanism involved in regulation of the development of HIV-1, and to uncover mode of action of antibiotic Tagetitoxin. The proposed research will add to these techniques and will provide new tools for investigation of the first step of gene expression as well as for design and testing of novel drugs.