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

细胞存活的核心是对基因表达的适当调节，基因是携带制造蛋白质指令的DNA单位。大多数已知的调控机制发生在基因表达开始时，即蛋白质合成刚刚开始的时候。由于研究人员对一种独特的小蛋白质如何保护蜜蜂免受细菌感染的研究，他们意识到，当编码蛋白质的合成已经完成时，基因表达也可以被调节。在这个项目中，研究人员将调查这种以前未知的基因表达调节机制有多普遍，并将进一步探索细胞中保护它不正常工作的元素。这些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。研究结果将被纳入研究人员的教学和社区服务活动中。该项目的研究结果将通过在国家和国际会议上的报告以及在同行评议期刊上的出版物向科学界通报。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，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时的行为可能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），一种揭示翻译核糖体基因组位置的方法，将有助于鉴定大肠杆菌中蛋白质合成结束缓慢的基因。结合结构研究的生化方法将有助于阐明完成蛋白与调节基因表达终止期的“母”核糖体之间的持续相互作用。拟议的研究将促进我们对先前未知的翻译调控层的理解，该层由新生蛋白和核糖体之间的相互作用控制。该项目的发现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。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.