PEX7 AND IT'S ROLE IN THE PATHOGENESIS OF RCDP

PEX7 及其在 RCDP 发病机制中的作用

• 批准号: 6697287
• 负责人: Nancy Elise Braverman
• 金额: $ 29.38万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-28 至 2006-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6697287
• 关键词: X ray; achondroplasia; alleles; cell proliferation; family genetics; gene mutation; genetic models; genetically modified animals; immunocytochemistry; immunofluorescence technique; immunoprecipitation; in situ hybridization; laboratory mouse; northern blottings; pathologic process; peroxisome; phenotype; polymerase chain reaction; protein binding; protein structure function; protein transport; southern blotting; western blottings; yeast two hybrid system

DESCRIPTION (Adapted from investigator's abstract): Rhizomelic chondrodysplasio punctata (RCDP) is a peroxisome biogenesis disorder characterized by cataracts, skeletal abnormalities, profound growth failure and mental retardation. RCDP is inherited as an autosomal recessive trait and is caused by mutations in PEX7, which encodes Pex7p, the receptor for peroxisomal enzymes having a PTS2 sequence. The specific steps involved in the import of PTS2 proteins into peroxisomes are not known, but the P.I. favors a model in which Pex7p binds PTS2 proteins in the cytosol and transports them to the peroxisome. Pex7p contains six WD40 motifs that determine a beta propeller, a structure that provides multiple rigid surfaces for protein interactions. In RCDP, defective function of PTS2 enzymes is thought to produce unknown metabolic alterations that determine the RCDP phenotype. The overall goal of this proposal is to study the molecular and cellular biology of Pex7p and the pathogenesis of RCDP. The P.I. will achieve this by identification and functional analysis of disease related PEX7 mutations in 50+ RCDP probands, and functional analysis of wild type Pex7p. Dr. Braverman will evaluate Pex7p expression, subcellular location and ability to mediate PTS2 protein import. She will also determine the regions of Pex7p that bind PTS2 and interact with other peroxins. These studies will define the steps in PTS2 protein import and allow correlation of PEX7 defects with variations in RCDP phenotypes. The P.I. will generate a murine model of RCDP to investigate the biochemical alterations in PTS2 protein pathways and their relation to tissue pathology. The proposed strategy will utilize cre/lox technologies to engineer hypomorphic, null and conditional PEX7 alleles and produce mice with combinations of these alleles to develop useful models of RCDP. These mice will be characterized by clinical, radiological, histological and biochemical evaluations. This information will contribute to understanding the pathophysiology of RCDP as well as the normal biology of peroxisome assembly and function in bone, lens and CNS development.

描述（改编自研究者的摘要）：根状软骨发育不良 点状（RCDP）是一种以白内障为特征的过氧化物酶体生物发生障碍， 骨骼异常、严重生长障碍和智力低下。 RCDP 是 作为常染色体隐性遗传，由 PEX7 突变引起， 编码 Pex7p，具有 PTS2 的过氧化物酶体酶受体 顺序。 PTS2蛋白导入的具体步骤 过氧化物酶体尚不清楚，但 P.I.支持 Pex7p 结合的模型 PTS2 蛋白存在于细胞质中，并将其转运至过氧化物酶体。 Pex7p 包含六个决定 β 螺旋桨的 WD40 基序，该结构 为蛋白质相互作用提供多个刚性表面。在 RCDP 中，有缺陷 PTS2 酶的功能被认为会产生未知的代谢改变 决定 RCDP 表型。该提案的总体目标是 研究Pex7p的分子和细胞生物学以及RCDP的发病机制。 P.I.将通过疾病的识别和功能分析来实现这一目标 50+ RCDP先证者的相关PEX7突变，以及野生型的功能分析 类型 Pex7p。 Braverman 博士将评估 Pex7p 表达、亚细胞定位 以及介导 PTS2 蛋白输入的能力。她还将确定地区 Pex7p 结合 PTS2 并与其他过氧化物酶相互作用。这些研究将 定义 PTS2 蛋白导入的步骤并允许 PEX7 缺陷的关联 RCDP 表型存在差异。 P.I.将生成一个小鼠模型 RCDP 研究 PTS2 蛋白通路的生化改变 它们与组织病理学的关系。拟议的策略将利用 cre/lox 设计低效、无效和有条件的 PEX7 等位基因的技术 产生具有这些等位基因组合的小鼠以开发有用的模型 RCDP。这些小鼠的特征是临床、放射学、组织学 和生化评估。这些信息将有助于理解 RCDP 的病理生理学以及过氧化物酶体的正常生物学 骨骼、晶状体和中枢神经系统发育中的组装和功能。