CARNITINE TRANSPORTER IN HUMAN DISEASE

人类疾病中的肉碱转运蛋白

• 批准号: 6128234
• 负责人: NICOLA LONGO
• 金额: $ 21.9万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6128234
• 关键词: CHO cells; allosteric site; binding sites; carnitine; chimeric proteins; clinical research; confocal scanning microscopy; family genetics; gene mutation; genetic disorder; human subject; inborn metabolism disorder; membrane transport proteins; mutant; site directed mutagenesis; sodium ion

DESCRIPTION (Adapted from applicant's abstract): (From the application abstract) Primary carnitine deficiency is an autosomal recessive disorder caused by defective carnitine transport. Carnitine is essential for fatty acid oxidation, and its deficiency results in hypoketotic hypoglycemia, skeletal and heart myopathy which are preventable by dietary carnitine. The Organic Cation Transporter with Nucleoside binding site (OCTN2) is a high-affinity carnitine transporter, which was cloned based on its homology with OCTN1 (which does not transport carnitine). Its role in carnitine deficiency was confirmed by the identification of nonsense mutations in OCTN2 in patients with early presentation of primary carnitine deficiency. The principal investigator proposes to test the hypothesis that families with primary carnitine deficiency have a spectrum of mutations in the organic cation transporter OCTN2, and that the degree of functional impairment of the transporter caused by these mutations correlates with the severity of the clinical presentation. To test this hypothesis, the following specific aims will be pursued: 1) Identification of mutations in the OCTN2 gene in families with primary carnitine deficiency. 2) Expression of missense mutations identified in these patients in Chinese Hamster Ovary (CHO) cells to confirm their causative role and to characterize their effect on carnitine transport. A correlation will be established between phenotype of the proband and residual carnitine transporter activity of the relative mutant. 3) Definition of domains of OCTN2 involved in carnitine recognition and transfer by evaluating carnitine transport in chimeric transporters, created by swapping domains between homologous portions of OCTNI and OCTN2. 4) Construction of site-directed mutations in critical domains of the OCTN2 carnitine transporter and determination of their effect on carnitine transport. This research will characterize mutations responsible for primary carnitine deficiency and clarify the function of a new class of membrane transporters whose alteration may cause other types of human diseases.

描述（改编自申请人的摘要）：（来自申请 摘要）原发性肉碱缺乏症是一种常染色体隐性遗传病 由肉碱运输缺陷引起。肉碱是脂肪酸所必需的 氧化，其缺乏会导致低酮性低血糖、骨骼和 可以通过膳食肉碱预防的心肌病。有机阳离子 具有核苷结合位点 (OCTN2) 的转运蛋白是一种高亲和力肉碱 转运蛋白，根据其与 OCTN1（不 运输肉碱）。它在肉碱缺乏症中的作用已被证实 早期癌症患者 OCTN2 无义突变的鉴定 原发性肉碱缺乏症的表现。首席研究员 提议检验以下假设：患有原发性肉碱缺乏症的家庭 有机阳离子转运蛋白 OCTN2 存在一系列突变，并且 由这些引起的转运蛋白功能损伤的程度 突变与临床表现的严重程度相关。测试 根据这一假设，将追求以下具体目标：1）识别 原发性肉碱缺乏症家庭中 OCTN2 基因突变的研究。 2）在这些中国患者中发现的错义突变的表达 仓鼠卵巢 (CHO) 细胞确认其致病作用并表征 它们对肉碱转运的影响。之间将建立相关性 先证者的表型和残留肉碱转运蛋白活性 相对突变体。 3）肉毒碱涉及的OCTN2结构域定义 通过评估嵌合体中的肉毒碱转运来识别和转移 转运蛋白，通过在 OCTNI 的同源部分之间交换域而创建 和 OCTN2。 4）在关键域中构建定点突变 OCTN2肉碱转运蛋白及其对肉碱的影响的测定 运输。这项研究将表征导致原发性突变的突变 肉碱缺乏症和阐明一类新型膜的功能 其改变可能导致其他类型的人类疾病的转运蛋白。