Molecular Mechanisms of Lipid Droplet Biogenesis

描述（由申请人提供）：代谢性疾病的患病率在美国已达到流行病的比例。在细胞中，营养素以三酰甘油（即at）的形式储存在脂滴（LD）中，脂滴是一种保守的内质网衍生的细胞器，由中性脂质核心组成，周围是用调节蛋白修饰的磷脂单层。三酰甘油在LD中的储存不仅对能量产生至关重要，并且作为膜前体的来源，而且是代谢疾病（如肥胖症、糖尿病和心血管疾病）的发病机制的核心，并且与衰老和癌症有关。多年来，LD被认为是惰性的细胞质脂肪球，科学研究界对此兴趣不大。认识到LD是整体参与多种疾病的病因学和LD是非常动态的细胞器铺平了道路，为一个新兴的研究领域，有可能对未来的治疗策略产生重大影响的代谢性疾病。LD从根本上起着细胞脂质代谢中心的作用，我们必须了解调节LD生物发生和功能的机制。因此，我建议的研究将具体：1）利用先进的功能基因组学策略来生成人类细胞中LD生物发生所需的所有基因的高密度上位图，2）使用代谢组学技术来定义ER-LD泛素化机制在LD生物发生和脂质代谢中的功能影响，3）利用邻近标记蛋白质组学方法确定LD生物发生的ER亚结构域，并确定LD蛋白质组成熟的时间动态。这些互补研究的整合将通过推进我们对LD生物发生机制和人类疾病中LD功能障碍的分子基础的理解，在细胞生物学和代谢疾病治疗策略方面开辟新天地。

DESCRIPTION (provided by applicant): The prevalence of metabolic diseases has reached epidemic proportions in the United States. In cells, nutrients are stored as triacylglycerol (i.e. at) in lipid droplets (LDs), a conserved endoplasmic reticulum-derived organelle that is consists of a neutral lipid core encircled by a phospholipid monolayer decorated with regulatory proteins. Storage of triacylglycerol in LDs is not only critical for energy production and as a source of membrane precursors, but is central to the pathogenesis of metabolic diseases, such as obesity, diabetes, and cardiovascular disease, and has been linked to aging and cancer. For years LDs were thought of as inert cytoplasmic fat globules and there was little interest among the scientific research community. The recognition that LDs are integrally involved in the etiology of multiple diseases and that LDs are extremely dynamic organelles has paved the way for a burgeoning area of research with the potential to make a significant impact on future treatment strategies for metabolic diseases. LDs fundamentally function as hubs of cellular lipid metabolism, and it is essential that we understand the mechanisms that regulate LD biogenesis and function. Therefore, my proposed research will specifically: 1) Exploit advanced functional genomic strategies to generate a high-density epistatic map of all genes required for LD biogenesis in human cells, 2) Use metabolomics technologies to define the functional impact of ER-LD ubiquitination machinery in LD biogenesis and lipid metabolism, and 3) Utilize proximity labeling proteomic methods to define ER subdomains specialized for LD biogenesis and to determine the temporal dynamics of LD proteome maturation. Integration of these complementary studies will break new ground in cell biology and metabolic disease treatment strategies by advancing our understanding of the mechanisms underlying LD biogenesis and the molecular basis of LD dysfunction in human diseases.