Bulk Flow Trafficking of Proteins within the Endoplasmic Reticulum

内质网内蛋白质的批量运输

• 批准号: 9051273
• 负责人: Laura Westrate
• 金额: $ 5.61万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9051273
• 关键词: Affect; Area; Binding; COPII-Coated Vesicles; COS-7 Cell; Calnexin; Carrier Proteins; Cell Maintenance; Cells; Cytosol; Endoplasmic Reticulum; Endosomes; Golgi Apparatus; Grant; Health; Homeostasis; Label; Lipids; Location; Mechanics; Membrane; Membrane Proteins; Methods; Microscopy; Morphology; Movement; Neurons; Nuclear Envelope; Organelles; Peripheral; Play; Process; Protein Biosynthesis; Protein Export Pathway; Proteins; RTN4 gene; Research Proposals; Role; Shapes; Signal Transduction; Site; Sorting - Cell Movement; Stretching; Surface; Techniques; Tubular formation; Work; base; calreticulin; electron tomography; insight; luminal membrane; migration; novel; overexpression; protein distribution; protein transport; public health relevance; receptor; reticulum cell; scaffold; trafficking

 DESCRIPTION (provided by applicant): The endoplasmic reticulum (ER) is a membrane bound organelle that stretches throughout the cytosol while maintaining a single lumen and is composed of multiple domains including the nuclear envelope, peripheral ER tubules and sheets. The shape of the ER plays critical roles in sustaining ER function, like protein synthesis, while also providing a cellular scaffold through which other organelles interact and are supported. Additionally, the ER is responsible for trafficking up to one third of all proteins thatit synthesizes out to various cellular locations as a critical mechanism to maintain cellular health and homeostasis. This proposal aims to determine whether the distinct structural domains of the ER also play a role in regulating the trafficking of proteins through a bulk flow mechanism. This method of protein sorting acts in a non-selective method and is instead dependent on the structural features of the organelle, specifically, the ratio of membrane area to luminal volume. Protein transport through bulk flow has previously been demonstrated in other organelles such as the endosome and golgi and it is likely that the geometric constraints of the various ER domains also function to facilitate bulk flow transport of proteins. This proposal therefore aims t understand the mechanism by which ER proteins are trafficked throughout the ER and the impact that the shape of the peripheral ER has on protein trafficking and export. By altering the shape of the ER, Aim 1 of this proposal will determine 1) how the distribution of membrane and luminal proteins are altered following changes to the geometric profile of the ER and 2) how the trafficking and movement of membrane and luminal proteins are directly affected by the morphology of the ER. Results from this aim will provide mechanistic insight in the mechanisms regulating protein distribution throughout the ER and whether protein trafficking is regulated through a bulk flow dependent manner that is dependent on the geometric profile of the peripheral ER. Aim 2 of this proposal will determine how the shape of the ER regulates protein export by 1) determining the role of ER shape on the location of COPII labeled exit sites and 2) track accumulation of secretory cargo proteins at exit sites in proximity to peripheral ER sheets and tubules. Results from this aim will provide insight into how the shape of the ER can directly regulate the targeted export of proteins from the ER. At the completion of this proposal, the mechanism by which the structural profile of the peripheral ER regulates protein trafficking and export will be established.

 描述（由适用提供）：内质网（ER）是一种膜结合的细胞器，在整个细胞质中延伸，同时保持单个管腔，并由多个结构域组成，包括核包膜，外围ER管和板。 ER的形状在维持ER功能中起着关键作用，例如蛋白质合成， 同时还提供了其他细胞器相互作用并得到支持的细胞支架。此外，ER负责运输所有蛋白质的三分之一，这些蛋白质将各种细胞位置综合为维持细胞健康和稳态的关键机制。该提案旨在确定ER的不同结构结构域是否在通过批量流动机制来衡量蛋白质的运输方面是否发挥作用。这种蛋白质分选方法以非选择性方法起作用，而是取决于细胞器的结构特征，特别是膜面积与腔体积的比率。以前在其他细胞器（例如内体和Golfi）中已经证明了通过大量流动的蛋白质传输，并且各种ER结构域的几何约束也很可能还起作用，以促进蛋白质的散装流量转运。因此，该提案的目的是了解ER蛋白在整个ER中运输的机制以及外围ER形状对蛋白质运输和出口的影响。通过改变ER的形状，本提案的目标1将决定1）在变化ER的几何形状以及2）​​膜和膜蛋白的运输和运动如何直接受到ER的形态直接影响的膜和腔蛋白的分布如何改变。该目标的结果将提供控制整个ER蛋白质分布的机制，以及是否通过批量流量依赖性方式调节蛋白质运输，这些方式取决于外围ER的几何形状。该提案的目标2将决定ER的形状如何通过1）确定ER形状在Copii标记的出口位置的位置的作用和2）在出口位点的秘密货物蛋白在外围ER片和管子附近的轨道积累。该目标的结果将提供有关ER的形状如何直接调节ER的蛋白质导出的洞察力。该提案完成时，将建立外围ER调节蛋白质运输和出口的结构概况的机制。