Control of translation by the nascent protein after its full synthesis and release

细胞存活的核心是基因表达的适当调节，基因是携带蛋白质制造指令的DNA单元。大多数已知的调节机制发生在基因表达的开始，当蛋白质的合成刚刚开始时。由于研究人员对小蛋白如何独特地保护蜜蜂免受细菌感染的研究，他们意识到基因表达也可以在道路的尽头进行调节，当编码蛋白的合成已经完成时。在这个项目中，研究人员将研究这种以前未知的基因表达调控机制的普遍性，并将进一步探索细胞中保护其正常工作的元素。研究活动将有助于培养高中，大学和研究生课程的学生，以及博士后研究人员。研究结果将纳入研究人员开展的教学和社区服务活动。该项目的研究结果将通过在国家和国际会议上的介绍以及在同行评审的期刊上发表的文章传达给科学界。以前人们认为，一旦蛋白质完全合成，它就会从产生它的核糖体中自由扩散，然而，已经收集到的证据表明，情况并非总是如此：某些蛋白质，其合成已经完全完成，会留在核糖体中并与核糖体相互作用，并在翻译终止阶段影响核糖体的行为。蛋白质从核糖体释放过程中的行为可能会影响编码其他蛋白质的基因的表达。在这个项目中，核糖体分析（Ribo-Seq），一种揭示核糖体在全基因组范围内翻译位置的方法，将有助于鉴定蛋白质合成末端缓慢的大肠杆菌基因。结合结构研究的生化方法将有助于阐明完整蛋白质与调节基因表达终止阶段的“母亲”核糖体之间挥之不去的相互作用。拟议的研究将推进我们对由新生蛋白质和核糖体之间的相互作用控制的先前未知的翻译调控层的理解。该项目的研究结果可能会激发新的想法，以控制基因表达，以应对可变的生物和非生物条件。该奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的知识价值和更广泛的影响审查标准的支持。

The centerpiece of cell survival is the proper regulation of the expression of genes, the units of DNA that carry the instructions to make proteins. Most of the known regulatory mechanisms occur at the outset of gene expression, when the synthesis of the protein is just being initiated. Thanks to the researchers' studies on how uniquely a small protein protects honeybees from bacterial infections, they realized that gene expression can also be modulated at the end of the road, when the synthesis of the encoded protein has already been completed. In this project, the researchers will investigate how widespread is this formerly unknown mechanism of gene expression regulation and will further explore the elements in the cell that guard it from working properly. The research activities will contribute to training students from high school, college, and graduate programs, as well as postdoctoral researchers. The results will be incorporated in the teaching and community service activities that the researchers conduct. The findings of the project will be communicated to the scientific community through presentations in national and international meetings and by publications in peer-reviewed journals. It has formerly been assumed that once a protein is fully synthesized, it freely diffuses from the ribosome that has produced it. However, evidence has been gathered that this is not always the case: certain proteins, whose synthesis has been thoroughly completed, linger in and interact with the ribosome, and influence the behavior of ribosomes at the translation termination stage. The behavior of proteins during their release from the ribosome may impact the expression of genes encoding other proteins. During this project, ribosome profiling (Ribo- Seq), an approach that reveals the position of translating ribosomes genome wide, will help identify the Escherichia coli genes where the end of protein synthesis is sluggish. Biochemical approaches in combination with structural studies will help elucidate the lingering interactions of the completed protein with the “mother” ribosome that modulate the termination phase of gene expression. The proposed research will advance our understanding of a previously unknown layer of translation regulation controlled by interactions between the nascent protein and the ribosome. The findings of the project may spark new ideas to control gene expression in response to variable biotic and abiotic conditions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.