How to build a protein factory? Linking structure and function of the plant endoplasmic reticulum

地球上大部分的蛋白质和碳水化合物的食物供应都是通过植物分泌途径生产、加工和运输的。内质网（ER）是分泌途径中的第一个隔室，是蛋白质和脂质合成、组装、质量控制和输出的主要工厂。内质网还可用于生产对工业有重要意义的分子，如抗体、治疗药物和有价值的化学品。因此，从生物技术上讲，内质网在制定控制或提高植物生产力的策略方面具有巨大的潜力。内质网形成了一个高度动态的网络，由两个形态不同的区域组成：薄片和小管，它们以三向结连接在一起，形成一个松散的多边形结构。薄片和小管的形态与不同的功能特性有关。虽然这两种结构都存在于所有真核细胞中，但每种内质网结构的比例在细胞和物种之间有所不同，这可能与潜在的细胞过程和蛋白质分泌需求有关。例如，分泌细胞，如胰腺和唾液腺，显示更高比例的薄片。在植物中，网状蛋白（reticulon）和Lunapark蛋白（Lunapark）这两类蛋白可以分别改变内质网的形态，使其有利于小管或薄片。该项目将在蛋白质生产和运输方面将植物内质网结构与内质网生产力联系起来。为此，我们将使用ER成形蛋白改变ER结构，并分析特定ER结构特征（如更多的小管或片）或ER运动变化对蛋白质生产和运输的影响。这是一个令人兴奋的项目，因为对ER结构和生产力的深入了解将使植物的可持续农业生产能够满足地球日益增长的粮食需求和气候变化问题。该系统的潜在机制和法规以及生物技术应用的可能性将在未来为生物燃料、植物营养成分和病虫害防治、生物标志物和诊断等研究领域提供信息。

A great proportion of the planet's food supply for proteins and carbohydrates is produced, processed and transported through the plant secretory pathway. The endoplasmic reticulum (ER) forms the first compartment in the secretory pathway and is a major factory for protein and lipid synthesis, assembly, quality control, and export. The ER can also be used to produce molecules important for industry such as antibodies, therapeutics and valuable chemicals. Therefore, biotechnologically the ER has great potential for the development of strategies to manipulate or increase plant productivity. The ER forms a highly dynamic network composed of two morphologically distinct domains: sheets and tubules, which are joined at 3-way junctions to create a loose polygonal structure. The morphology of sheets and tubules has been related to different functional properties. Though both structures are present in all eukaryotic cells, the proportion of each ER structure varies between cells and species which could potentially be linked to the underlying cellular processes and the protein secretion requirements. For example, secretory cells, such as pancreatic and salivary glands, display a higher proportion of sheets. In plants two classes of proteins, reticulon and Lunapark proteins can change the ER network morphology in favour of tubules or sheets, respectively. This project will link structure of the plant ER with ER productivity in terms of protein production and transport.For this, we will change ER structure using ER-shaping proteins and analyse the impact of specific ER structural features such as more tubules or sheets or changes in the movement of the ER on protein production and transport.This is an exciting project as the in-depth knowledge about ER structure and productivity will enable sustainable agricultural production of plants to cater for the planet's increasing food demands and climate change issues. The underlying mechanisms and regulations as well as the possibilities of biotechnological applications of this system will in future inform research areas such as biofuel, plant nutritional composition and pest control, biomarkers and diagnostics.