Mechanisms of Translation Initiation Mediated by mRNA Structure

mRNA 结构介导的翻译起始机制

• 批准号: 10384393
• 负责人: Dmitri Ermolenko
• 金额: $ 5.08万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-05-01 至 2023-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10384393
• 关键词: Binding Proteins; Biological; Chemicals; Complex; Computational Biology; DNA; Development; Eukaryota; Human; Lead; Malignant Neoplasms; Mediating; Messenger RNA; Microscopy; Modeling; Molecular Biology; Peptide Initiation Factors; Physical Chemistry; Play; Process; Protein Biosynthesis; Proteins; RNA Probes; Regulation; Role; Spectrum Analysis; Structure; Testing; Translating; Translation Initiation; Translations; human disease; in vivo; lens; novel; nucleic acid structure; protein complex; recruit; single molecule; structural biology

Mechanisms of Translation Initiation Mediated by mRNA Structure The Central Dogma of molecular biology is that DNA is used to make mRNA, which is used to make proteins. The initiation of translation, the act of making proteins from messenger RNA (mRNA), is central to the regulation of this process. Dysregulation of translation initiation plays an important role in a number of human diseases including cancer. In eukaryotes including humans, the initiation of translation involves the recruitment of factors that interact with the two (5’ and 3’) ends of the mRNA to make, in essence, a circle that is poised to be translated. The recruitment of factors and the function of subsequent circularization are poorly understood. We aim to take a novel look at this biological problem through the lens of physical chemistry of nucleic acids and structural biology. Although factor-mediated circularization of mRNA is thought to be critical for protein synthesis, this proposal puts forward an alternative hypothesis: formation of basepairing interactions within the mRNA itself results in the circularization of the mRNA in the absence of the protein complexes. Hence, the ends of the mRNA are inherently located close to one another. Such “circularization” could facilitate the recruitment of the protein complexes and thereby aid translation initiation. To test our hypothesis, we will experimentally examine whether the ends of mRNAs are in close proximity in the absence of protein initiation complexes. We will also test whether the disruption of basepairing interactions between mRNA ends inhibits protein synthesis and binding of translation initiation factors to the mRNA. The proposed studies will span a spectrum of approaches including single-molecule fluorescent microscopy and fluorescent spectroscopy, chemical probing of RNA structure, computational biology and examination of translation in vivo. Our proposed studies will elucidate whether mRNA secondary structure and end-to-end distance are major determinants that govern translational initiation in eukaryotes.

由mRNA结构介导的翻译起始机理 分子生物学的中心教条是DNA用于制作mRNA，该mRNA用于制造蛋白质。 翻译的主动性是从信使RNA（mRNA）制作蛋白质的行为，是 该过程的调节。翻译计划的失调在许多人类中起着重要的作用 包括癌症在内的疾病。在包括人类在内的真核生物中，翻译的主动性涉及招聘 与mRNA的两个（5'和3'）相互作用的因素，从本质上讲是一个被中毒的圆 被翻译。招募因素和随后的循环作用的功能知之甚少。 我们的目的是通过核酸的物理化学镜头对这种生物学问题进行新颖的研究 尽管因子介导的mRNA的电路被认为对蛋白质至关重要，但结构生物学和结构生物学 综合，该提议提出了一个替代假设：在 在没有蛋白质复合物的情况下，mRNA本身会导致mRNA循环。因此， mRNA的末端固有地位于彼此附近。这种“循环”可以促进 募集蛋白质复合物，从而帮助翻译起始。为了检验我们的假设，我们将 实验检查在没有蛋白质引发的情况下，mRNA的末端是否处于接近状态 复合物。我们还将测试mRNA末端之间的基台相互作用的破坏是否抑制 蛋白质合成和翻译起始因子与mRNA的结合。提出的研究将跨越 包括单分子荧光显微镜和荧光光谱的方法频谱， RNA结构，计算生物学和体内翻译检查的化学探测。我们提出的 研究将阐明mRNA二级结构和端到端距离是否是主要决定者 管理真核生物的翻译启动。