Regulation of mRNA Partitioning to the Endoplasmic Reticulum

描述（由申请人提供）：在当代模型中，真核细胞分离不同类别蛋白质的合成;分泌/整合膜蛋白在内质网（ER）上产生，可溶性蛋白在胞质溶胶中产生。然而，最近的研究细胞质和ER室之间的mRNA分配，确定了一个突出的作用，ER在合成可溶性和分泌/membane蛋白质一样。除了描述ER在全球蛋白质合成中的新功能外，这些发现还确定了我们对真核细胞如何在两个隔室之间分配mRNA并反过来调节这两大类蛋白质合成的理解存在重大差距。为了解决这一差距，我们正在集中我们的研究工作，以1）了解真核细胞如何分配mRNAs之间的胞质溶胶和内质网（ER）和2）确定真核细胞如何调节蛋白质合成活性的胞质溶胶和ER区室在稳态和细胞应激。这项研究有望为健康和疾病中蛋白质合成的调控机制提供重要见解。此外，这项研究将为我们理解真核生物所必需的mRNA定位和蛋白质合成途径做出重大贡献。提出了三个具体目标：i）定义SRP途径在mRNA分配到ER中的体内作用; ii）鉴定赋予非典型mRNA分配到ER的mRNA定位信号; iii）定义ER隔室在胞质蛋白质合成中的全局作用。为了解决这些具体的目标，我们将使用哺乳动物组织培养细胞模型，并将强调建立细胞分级，细胞生物学分析报告mRNA定位在原位和分子生物学分析赋予ER定位的mRNA的结构/功能元件的生化技术。许多突出的人类疾病，包括肥胖症，糖尿病和中风激活细胞应激反应，深刻改变细胞合成的蛋白质的类型和数量，从而改变细胞活力。通过了解细胞在健康和疾病中如何决定每种蛋白质的种类和数量，我们将了解细胞对病理压力做出反应的基本机制。通过了解这些机制，我们希望确定治疗干预的新靶点。

DESCRIPTION (provided by applicant): In contemporary models, eukaryotic cells segregate the synthesis of different classes of proteins; secretory/integral membrane proteins are made on the endoplasmic reticulum (ER) and soluble proteins in the cytosol. Recent studies of mRNA partitioning between the cytosol and ER compartments have, however, identified a prominent role for the ER in the synthesis of both soluble and secretory/membane proteins alike. In addition to describing new functions for the ER in global protein synthesis, these findings identify a significant gap in our understanding of how eukaryotic cells partition mRNAs between the two compartments and in turn regulate the synthesis of these two broad classes of proteins. To address this gap, we are focusing our research efforts to 1) understand how eukaryotic cells partition mRNAs between the cytosol and the endoplasmic reticulum (ER) and 2) determine how eukaryotic cells regulate the protein synthesis activity of the cytosol and ER compartments during homeostasis and cell stress. This research is expected to provide significant insights into the regulatory mechanisms governing protein synthesis in health and disease. In addition, this research will serve as a significant contribution to our understanding of the mRNA localization and protein synthesis pathways that are essential to eukaryotic life. Three specific aims are proposed: i) Define the in vivo role of the SRP pathway in mRNA partitioning to the ER; ii) Identify the mRNA localization signals that confer non-canonical mRNA partitioning to the ER and iii) Define the global role of the ER compartment in cytosolic protein syntehsis. To address these specific aims, we will use mammalian tissue culture cell models and will emphasize established biochemical techniques of cell fractionation, cell biological analysis of reporter mRNA localization in situ and molecular biological analysis of the structure/function elements of mRNAs that confer ER localization. Many prominent human diseases, including obesity, diabetes and stroke activate cell stress responses that profoundly alter the types and amounts of proteins cells synthesize and consequently, cell viability. By understanding how cells decide which and how much of each protein to make, in health and disease, we will understand the basic mechanisms used by cells to respond to pathological stress. By understanding these mechanisms, we hope to identify new targets for therapeutic intervention.