Control of Storage Protein Biosynthesis by mRNA Targeting

以信使核糖核酸为靶标调控贮藏蛋白质的生物合成许多植物种子被用作食物，随着种群的增加，可以预期作为蛋白质来源的重要性将越来越大。虽然人们已经做出了相当大的努力来了解主要的种子蛋白基因是如何在细胞核中调节的，但对控制其RNA在细胞质中表达的细胞事件知之甚少。该实验室以前的努力已经证明，储存蛋白RNAs(和许多其他RNAs)在离开细胞核时不会立即转化为蛋白质。相反，它们形成大颗粒，沿着不同的路径运输到皮质区域，这是一个有利于蛋白质合成的位置，位于质膜之下。在这个项目中，将采用一种集成的分子、遗传和细胞成像方法(1)定义赋予RNA转运和靶向大脑皮层区域的邮政编码RNA序列，(2)分离识别这些邮政编码并赋予转运特异性的蛋白质因子，(3)确定这些RNA转运颗粒的蛋白质和RNA组成，以及(4)鉴定在RNA转运缺陷的几个水稻突变中的基因。这项研究将为RNA以及蛋白质如何在植物细胞中定位和积累提供新的见解。此外，它可能导致对控制碳和氮的利用及其转化为储存储备的机制的新见解，从而有助于努力提高种子质量和作物生产率。该项目将用于培养博士后、研究生和本科生层次的年轻科学家，并将为这些年轻科学家提供国际研究的机会。该项目还将有助于进一步开发由P.I.教授的关于真核细胞中蛋白质靶向的讲座课程，并将加强正在进行的关于种子质量和产量的遗传、生化和细胞方面的国际合作研究。

Control of Storage Protein Biosynthesis by mRNA TargetingMany plant seeds are used as food and, with the increase in population, can be expected to assume a greater importance as a source of protein. Although considerable effort has been directed at understanding how the major seed protein genes are regulated in the nucleus, very little is known about the cellular events that control the expression of their RNAs in the cytoplasm. Previous efforts from this laboratory have demonstrated that storage protein RNAs (and many other RNAs) are not immediately translated into protein when they exit the nucleus. Instead, they form large particles which are transported along different pathways to the cortical region, a site conducive for protein synthesis and located underneath the plasma membrane. In this project, an integrated molecular, genetic and cell imaging approach will be employed (1) to define the zip code RNA sequences that confer RNA transport and targeting to the cortical region, (2) to isolate the protein factors that recognize these zip codes and confer transport specificity, (3) to determine the protein and RNA composition of these RNA transport particles, and (4) to identify the genes in several rice mutants defective in RNA transport. This study will provide new insights into how RNAs and, in turn, proteins are localized and accumulated in plant cells. Moreover, it may lead to new insights into the mechanisms that control the utilization of carbon and nitrogen and their conversion into storage reserves and, thereby, aid in efforts to increase seed quality and crop productivity. The project will serve to train young scientists at the postdoctoral, graduate and undergraduate levels and will provide these younger scientists the opportunity for international research. The project will also aid in further developing a lecture course on protein targeting in eukaryotic cells taught by the P.I., and will strengthen an ongoing international collaborative study on the genetic, biochemical and cellular aspects of seed quality and yields.