Functional diversity of specialized vesicles derived from the endoplasmic reticulum in plants

蛋白质在亚细胞间的运输是细胞生命中必不可少的基本过程。植物含有各种功能特化的小泡，这些小泡积累或运输对植物生长、发育和逆境反应至关重要的特定蛋白质。在十字花科植物(卷心菜和芥菜科植物)中，有一种特殊的囊泡，称为内质网(ER)小体，在组织受损时可以产生有毒化合物，作为对抗病原体和食草动物的“芥子油炸弹”。内质网小体及其相关的化学库被认为只存在于十字花科植物中，但最近的研究表明，所有植物中都存在内质网小体相关的小泡。这些囊泡的功能尚不清楚。这个项目试图了解这些与内质网身体相关的小泡，以及它们如何对植物生物功能的多样性做出贡献。这个项目的更广泛的影响包括教授和培训学生进行他们自己的微型研究项目，PI还将作为高中科学博览会的导师参加。囊泡介导的蛋白质在亚细胞间的转运是细胞生命的一个基本过程。植物含有各种功能特化的内质网衍生小泡(ERDV)，这些小泡积累或运输对植物生长、发育和逆境途径至关重要的特定蛋白质。在高度保守的分泌途径中，内质网合成的蛋白质折叠并通过COPII包被的小泡传递到高尔基体，然后运输到其他亚细胞室。然而，在植物细胞中，一些特定的内质网合成的蛋白质进入专门的ERDV，并以不依赖高尔基体的方式运输到其他隔室。十字花科植物中的ER小体是一种专门的ERDV，能产生对抗食草动物和病原体的有毒化学物质。这些内质网小体仅在十字花科植物中发现，其来源尚不清楚。NAI2是一种内质网小体蛋白，只有在油菜中才有同源物，是内质网小体形成所必需的。来自拟南芥的三个相关的NAI2相互作用蛋白(NAIP1到NAIP3)也是内质网形成所必需的，但在所有植物中都有同源蛋白。NAIP1与内质网小体特异相关，NAIP2和NAIP3也与含有其他蛋白的相关ERDV相关。因此，在所有植物中都有一个与内质网身体相关的、含有NAP的囊泡的新家族。本项目的目标是通过鉴定NAIP囊泡的货运蛋白、确定NAIP囊泡的调节作用以及分析对NAIP囊泡的生物发生起重要作用的其他因素来建立NAIP囊泡的功能多样性。该项目的进展将加强对植物特性的分子基础的理解，如种子萌发、维管发育和植物防御，这些特性具有广泛的应用，包括在农业环境中的应用。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Protein trafficking between subcellular compartments is an essential and basic process of cellular life. Plants contain various types of functionally specialized vesicles that accumulate or transport specific proteins important for plant growth, development, and stress responses. In Brassica plants (plants in the cabbage and mustard family), there are specialized vesicles called endoplasmic reticulum (ER) bodies that can generate toxic compounds upon tissue damage as a “mustard oil bomb” against pathogens and herbivores. ER bodies and their associated chemical arsenal were thought to occur only in Brassica plants, but recent studies have shown that ER body-related vesicles are present in all plants. The functions of these vesicles are unknown. This project seeks to understand these ER body-related vesicles and how they contribute to the diversity of biological functions in plants. The Broader Impacts of this project include teaching and training students to conduct their own mini-research projects and the PI will also participate as a mentor for high school science fairs. Vesicle-mediated protein trafficking between subcellular compartments is a basic process of cellular life. Plants contain various types of functionally specialized, ER-derived vesicles (ERDVs) that accumulate or transport specific proteins important for plant growth, development, and stress pathways. In the highly conserved secretory pathway, ER-synthesized proteins fold and pass onto the Golgi apparatus through COPII-coated vesicles before transport to other subcellular compartments. However, in plant cells, some specific ER-synthesized proteins pass into specialized ERDVs and are transported to other compartments in a Golgi-independent manner. ER bodies in Brassica plants are specialized ERDVs that generate toxic chemicals against herbivores and pathogens. These ER bodies are found only in Brassica plants and their origins are unknown. NAI2 is an ER body protein with homologs only in Brassica and is required for ER body formation. Three related NAI2-interacting proteins (NAIP1 to 3) from Arabidopsis are also required for ER body formation but have homologs in all plants. While NAIP1 is specifically associated with ER bodies, NAIP2 and 3 are also associated with related ERDVs containing other proteins. Thus, there is a novel family of ER body-related, NAIP-containing vesicles in all plants. The goal of this project is to establish the functional diversity of the NAIP vesicles by identifying their cargo proteins, determining the regulatory roles of NAIP vesicles, and analyzing additional factors important for the biogenesis of NAIP vesicles. Progress of this project will enhance the understanding of the molecular basis of plant traits such as seed germination, vascular development, and plant defense, which has a multitude of applications, including those in the agricultural setting.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.