Cell Biology of Human Vit C Transporters in Liver Cells

肝细胞中人类维生素 C 转运蛋白的细胞生物学

• 批准号: 7219505
• 负责人: VEEDAMALI S SUBRAMANIAN
• 金额: $ 12.5万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-10 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7219505
• 关键词: Actins; Area; Ascorbic Acid; Ascorbic Acid Deficiency; Biochemical; Biological; Biological Models; Blood Circulation; Cardiovascular Diseases; Carrier Proteins; Cataract; Cell hybridization; Cell membrane; Cell model; Cell physiology; Cell surface; Cells; Cellular biology; Chimeric Proteins; Clinical; Confocal Microscopy; Connective Tissue Diseases; Development; Development Plans; Disease; Epithelial; Epithelial Cells; Event; Fibroblasts; Gall Bladder Diseases; Glucuronic Acid; Glucuronic Acids; Goals; Green Fluorescent Proteins; Growth; Hand; Health; Hepatocyte; Homeostasis; Human; Hybrid Cells; Image; Impaired wound healing; Impairment; In Vitro; Indium; Integral Membrane Protein; Investigation; Lead; Learning; Leucine; Life; Liver; Liver diseases; Malignant Neoplasms; Mammals; Mediating; Membrane; Membrane Protein Traffic; Membrane Proteins; Membrane Transport Proteins; Methods; Microfilaments; Micronutrients; Microtubules; Modeling; Molecular; Molecular Biology Techniques; Motor; Movement; Nature; Nutrient; Organ; Pathway interactions; Pattern; Personal Satisfaction; Physiological; Physiology; Play; Principal Investigator; Process; Proline; Protein Isoforms; Protein Kinase; Protein Kinase C; Proteins; Purpose; Rattus; Regulation; Reporting; Research; Research Design; Research Personnel; Retrieval; Role; Signal Transduction; Site; Sodium; Sorting - Cell Movement; System; Tissues; Transport Process; Tyrosine; Vasomotor; Vesicle; Vitamins; Water; Work; base; bone; career; non-alcoholic; polypeptide; programs; trafficking

DESCRIPTION (provided by candidate): The main purpose of this research career development plan is to allow the Principle Investigator to learn recent advances in imaging and molecular biology techniques, boosting his career goal to become an independent academic investigator in the area of cell biology with an emphasis on the intracellular traficking and membrane targeting of different transporters in epithelial and nonepithelial cellular systems relating the work to human health and disease. Ascorbic acid (vitamin C) is an essential micronutrient required for normal human health and well being. Recently two isoforms of the human sodium-dependent vitamin C transporters (hSVCT1 and hSVCT2) have been cloned and their abundant expression has been reported in human liver and other tissues. Nothing is known about the mechanisms that dictate the hSVCT1 and hSVCT2 targeting to the human liver hepatocyte cell surface. Membrane targeting and polarized expression of membrane transporters is not only important in order to establish polarity in epithelial cells, but is also vital when studying regulation via insertion/retrival of membrane transporters. Further, recent studies have shown that impairment in a transport event could be mediated via defective trafficking/mis-targeting of the transport carriers to the cell membrane. Therefore, research on the membrane targeting and intracellular trafficking of transport carriers is important from cell biology/physiology standpoints. Targeting of a protein to the plasma membrane has been shown to involve specific targeting signals such as tyrosine, di-leucine, di-acidic, dibasic, proline rich and PDZ domains embedded in the polypeptide. Using HepG2 and Wif-B9 cells as models, our specific aims are:1) To identify the molecular mechanisms that mediate the targeting of the hSVCT1 and hSVCT2 proteins to the plasma membrane by employing confocal imaging, 2) Determine what role the microtubule network and the actin microfilaments play in intracellular trafficking of hSVCT1 and hSVCT2, investigate if these trafficking events involve vesicles and motor proteins, and if they are regulated by specific protein kinase-mediated pathways. A combination of cell/biochemical/molecular biological and imaging methods will be used in these investigations. The research described in this proposal will not only enable the applicant to achieve his career goals, but will also contribute to a better understanding of the cell biology and regulation of vitamin C transporters in particular, and transporters of other nutrients in general.

描述（由候选人提供）： 该研究职业发展计划的主要目的是让主要研究者学习成像和分子生物学技术的最新进展，推动他的职业目标成为细胞生物学领域的独立学术研究者，重点是上皮和非上皮细胞系统中不同转运蛋白的细胞内运输和膜靶向，与人类健康和疾病相关。抗坏血酸（维生素C）是正常人类健康和福祉所需的必需微量营养素。近年来，人类钠依赖性维生素C转运蛋白的两种亚型（hSVCT 1和hSVCT 2）被克隆，并已报道其在人类肝脏和其他组织中大量表达。目前还不清楚hSVCT 1和hSVCT 2靶向人肝细胞表面的机制。膜转运蛋白的膜靶向和极化表达不仅对于在上皮细胞中建立极性是重要的，而且在研究通过插入/检索膜转运蛋白的调节时也是至关重要的。此外，最近的研究表明，运输事件中的损伤可以通过运输载体向细胞膜的缺陷性运输/错误靶向来介导。因此，从细胞生物学/生理学的角度来看，研究转运载体的膜靶向和细胞内运输是重要的。蛋白质靶向质膜已显示涉及特异性靶向信号，如酪氨酸、二亮氨酸、二酸、二元、富含脯氨酸和嵌入多肽中的PDZ结构域。本研究以HepG 2和Wif-B 9细胞为模型，通过共聚焦成像技术，探讨hSVCT 1和hSVCT 2蛋白靶向细胞膜的分子机制，并研究微管网络和肌动蛋白微丝在hSVCT 1和hSVCT 2的细胞内转运中的作用，探讨这些转运过程是否涉及囊泡和马达蛋白，以及它们是否受蛋白激酶介导的特定途径的调控。在这些调查中将使用细胞/生物化学/分子生物学和成像方法的组合。本提案中描述的研究不仅使申请人能够实现其职业目标，而且还有助于更好地了解细胞生物学和维生素C转运蛋白的调节，以及其他营养素的转运蛋白。