Intracellular Transport: The Mannose Phosphate Receptor

细胞内运输：甘露糖磷酸受体

• 批准号: 7990866
• 负责人: Suzanne R Pfeffer
• 金额: $ 9.88万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-12-10 至 2011-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7990866
• 关键词: ATP Hydrolysis; ATP phosphohydrolase; Area; Back; Binding; Biochemical; Biological; Blood Circulation; Catalytic Domain; Cell physiology; Cells; Cholera Toxin; Cholesterol; Complex; Computer software; Confusion; Cultured Cells; Defect; Diabetes Mellitus; Disease; Early Endosome; Enzymes; Event; Genome; Goals; Golgi Apparatus; Guanosine Triphosphate Phosphohydrolases; Heart Diseases; Hela Cells; Human; IGF Type 2 Receptor; Immune system; Insulin; Intracellular Transport; Investigation; Lysosomes; Malignant Neoplasms; Mammalian Cell; Mannose; Mediating; Membrane Protein Traffic; Molecular; Monitor; Pathway interactions; Peripheral; Process; Protein Binding; Proteins; Recycling; Research; Role; Route; SNAP receptor; Small Interfering RNA; Sorting - Cell Movement; Surface; Testing; Transferrin Receptor; Transport Vesicles; Vesicle; Virus Diseases; Work; base; genome wide association study; genome-wide; inorganic phosphate; interest; killings; late endosome; nervous system disorder; novel; pathogen; protein function; public health relevance; receptor; receptor recycling; research study; syntaxin 6; trafficking; trans-Golgi Network

DESCRIPTION (provided by applicant): The long term goal of this research is to determine the molecular basis of membrane traffic in mammalian cells. The focus is on mannose 6-phosphate receptors (MPRs) that deliver newly synthesized lysosomal enzymes from the Golgi to pre-lysosomes, and then return to the Golgi to pick up more cargo. Several recently discovered proteins are needed for MPR transport from late endosomes to the trans Golgi network: a cargo selection protein that recognizes the MPRs in late endosomes (TIP47), a pathway- specific SNARE complex for fusion of MPR-vesicles at the TGN, and two proteins that function in vesicle tethering at the Golgi (GCC185 and RhoBTB3). The goals of this application are (1) to define precisely, the distinct routes taken by cargoes that are transported from early endosomes back to the Golgi, with focus on MPRs in comparison with cholera toxin; (2) to carry out a genome-wide, automated siRNA screen for proteins needed for MPR recycling. The screen will make use of the fact that depletion of proteins needed for MPR recycling leads to dispersal of MPRs into peripherally localized cellular compartments. Computer software can detect this dispersal, permitting automated analysis of the effects of 22,000 siRNAs transfected into cultured cells. (3) Also proposed are experiments to further characterize two novel Rab9 effectors that are important for this trafficking pathway: RhoBTB3 and RUTBC1. In summary, these experiments open up entirely new areas of investigation in the area of MPR trafficking and will provide fundamental information regarding the mechanisms of receptor trafficking in human cells. The work has broad application to our understanding of a number of disease states including diabetes, cancer, heart disease and neurological disorders. PUBLIC HEALTH RELEVANCE: Membrane traffic is essential for our ability to both secrete and respond to insulin, to clear cholesterol from the bloodstream, and for cells of the immune system to kill pathogens. Defects in membrane traffic underlie a number of disease states and virus infection depends upon this process. By understanding the molecular events responsible for membrane traffic, we will be better able to intervene in a variety of disease states.

描述（由申请人提供）：本研究的长期目标是确定哺乳动物细胞膜运输的分子基础。重点是甘露糖6-磷酸受体（MPR），将新合成的溶酶体酶从高尔基体传递到前溶酶体，然后返回高尔基体以获得更多的货物。MPR从晚期内体转运到反式高尔基体网络需要几种最近发现的蛋白质：识别晚期内体中MPR的货物选择蛋白（TIP 47），用于在TGN处融合MPR-囊泡的途径特异性SNARE复合物，以及在高尔基体处的囊泡束缚中起作用的两种蛋白质（GCC 185和RhoBTB 3）。本申请的目标是（1）精确定义从早期内体转运回高尔基体的货物所采用的不同途径，重点是MPR与霍乱毒素的比较;（2）对MPR再循环所需的蛋白质进行全基因组自动siRNA筛选。该筛选将利用MPR再循环所需的蛋白质的耗尽导致MPR分散到外周局部细胞区室中的事实。计算机软件可以检测这种分散，允许自动分析转染到培养细胞中的22，000个siRNA的影响。(3)还提出了实验，以进一步表征两个新的Rab 9效应器，这是重要的，这种贩运途径：RhoBTB 3和RUTBC 1。总之，这些实验开辟了MPR运输领域的全新研究领域，并将提供有关人类细胞中受体运输机制的基本信息。这项工作对我们理解包括糖尿病、癌症、心脏病和神经系统疾病在内的许多疾病状态具有广泛的应用。公共卫生关系：膜运输对于我们分泌和响应胰岛素、清除血液中的胆固醇以及免疫系统细胞杀死病原体的能力至关重要。膜运输缺陷是许多疾病状态的基础，病毒感染取决于这一过程。通过了解负责膜交通的分子事件，我们将能够更好地干预各种疾病状态。