MECHANISMS OF ORGANELLE BIOGENESIS AT THE ENDOPLASMIC RETICULUM SUBDOMAINS

内质网亚域细胞器生物发生机制

• 批准号: 10797317
• 负责人: Amit Joshi
• 金额: $ 24.55万
• 依托单位: UNIVERSITY OF TENNESSEE KNOXVILLE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-15 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10797317
• 关键词: Binding; Biogenesis; C2 Domain; Cell Culture Techniques; Cells; Cellular biology; Defect; Disease; Endoplasmic Reticulum; Eukaryota; Eukaryotic Cell; Family; Fatty Liver; Functional disorder; Goals; Integral Membrane Protein; Intracellular Membranes; Life; Lipids; Lipodystrophy; Mammalian Cell; Medical; Membrane; Metabolic Diseases; Mitochondria; Morphology; Non-Insulin-Dependent Diabetes Mellitus; Nuclear Envelope; Organelles; Play; Proteins; Research; Role; Saccharomyces cerevisiae; Testing; Vesicle; Work; Yeasts; Zellweger Syndrome; fatty liver disease; nervous system disorder; peroxisome; therapeutic target

PROJECT SUMMARY Intracellular membrane-bound organelles are a hallmark of all eukaryotic cells. Understanding how cells generate different organelles remains one of the central problems in cell biology. Some organelles, like the endoplasmic reticulum (ER) and mitochondria, are self-generating whereas other organelles can be generated de novo. The ER plays a central role in organelle biogenesis. Even though the ER is a single continuous membrane that extends from the outer nuclear envelope into the periphery of the cell, there are discrete regions in the ER membrane called ER subdomains. Nascent peroxisomes and lipid droplets (LDs) form at specialized ER subdomains. Remarkably, little is known about these ER subdomains and their role in regulating organelle biogenesis. The goal of our research is to determine the mechanisms of peroxisome and LD biogenesis by detailed characterization of the discrete ER subdomains using S. cerevisiae and mammalian cell culture. Previously, we identified a family of reticulon-like ER membrane tubulating proteins, Pex30 in yeasts and multiple C2 domains containing transmembrane proteins, MCTP1 and MCTP2, in higher eukaryotes. We demonstrated that both Pex30 and MCTPs are localized at discrete ER subdomains where nascent pre-peroxisomal vesicles and LDs are formed. Based on these findings, we proposed to identify the proteins and lipids enriched at the specialized ER subdomains using unbiased as well as candidate-based approaches. We will then test the effects of modulating the functions of candidate proteins and lipids on the formation, abundance, morphology, and distribution of peroxisomes and LDs. Investigating the mechanistic details of peroxisomes and LDs biogenesis from these ER subdomains is not only important for understanding basic principles of cell biology but also has critical medical implications. Several life-threatening neurological disorders including Zellweger syndrome associated with peroxisomal defects and metabolic disorders such as type 2 diabetes and fatty liver disease caused due to LD defects have no cure. Determining the mechanisms of organelle biogenesis will have implications in understanding the pathophysiology of these disorders and provide us hints for potential therapeutic targets.

项目概要 细胞内膜结合细胞器是所有真核细胞的标志。了解细胞如何 产生不同的细胞器仍然是细胞生物学的核心问题之一。一些细胞器，例如 内质网（ER）和线粒体是自我生成的，而其他细胞器可以是 从头生成。 ER 在细胞器生物发生中起着核心作用。尽管 ER 是单一的 从外核膜延伸到细胞外围的连续膜，有 内质网膜上的离散区域称为内质网亚结构域。新生过氧化物酶体和脂滴 (LD) 形成于专门的 ER 子域。值得注意的是，人们对这些 ER 子域及其作用知之甚少 调节细胞器的生物发生。我们研究的目标是确定过氧化物酶体的机制 和 LD 生物发生，通过使用酿酒酵母对离散的 ER 子域进行详细表征， 哺乳动物细胞培养。之前，我们鉴定了一个类网状内质网膜管蛋白家族， 酵母中的 Pex30 和含有跨膜蛋白 MCTP1 和 MCTP2 的多个 C2 结构域 高等真核生物。我们证明 Pex30 和 MCTP 都位于离散的 ER 子域 新生的前过氧化物酶体囊泡和 LD 在此形成。基于这些发现，我们建议 使用无偏见和 基于候选人的方法。然后我们将测试调节候选蛋白质功能的效果 和脂质对过氧化物酶体和LD的形成、丰度、形态和分布的影响。调查中 来自这些 ER 子域的过氧化物酶体和 LD 生物发生的机制细节不仅是 对于理解细胞生物学的基本原理很重要，而且也具有重要的医学意义。一些 危及生命的神经系统疾病，包括与过氧化物酶体缺陷相关的齐薇格综合征 而LD缺陷引起的2型糖尿病、脂肪肝等代谢性疾病则无 治愈。确定细胞器生物发生的机制将有助于理解 这些疾病的病理生理学并为我们提供潜在治疗靶点的提示。