Defining the Role of MAGP-2 in Microfibril Assembly

描述(申请人摘要)：微原纤维相关糖蛋白-2 (MAGP-2)是两个MAGP之一，这两个MAGP都是 与弹性纤维有关的微细纤维。MAGP-2在这里显示为结合 特别是原纤维蛋白-1和-2，两个特征良好的成分 与遗传性疾病有关的细胞外微纤维 称为马凡综合征和先天性宫缩的弹性纤维 分别为蜘蛛状指。MAGP-2还与MAGP-1结合。在这项提议中， 我们将研究MAGP-2在微原纤维中的功能。MAGP-2结合 原纤维蛋白-1和MAGP-1上的位点以及决定簇都将被本地化 在MAGP-2中负责这些。MAGP-2的时空分布特征 将确定发育中的小鼠的基因表达，并 与其他主要弹性纤维成分的共表达/共定位 评估过了。在MAGP-1基因敲除小鼠中MAGP-2的表达也将 调查过了。携带MAGP-2基因靶向破坏的小鼠将 生成并评估发育异常。微纤丝在 MAGP-2-/-小鼠将在超微结构水平上进行研究。如果老鼠死了 在胚胎发育期间，原代成纤维细胞培养将来自 并用于研究MAGP-2在微原纤维组装中的作用 在试管中。MAGP-2在肺分支形态发生中的作用也将是 在淘汰赛中研究他们的肺是否发育异常。如果MAGP-2-/- 小鼠缺乏明显的表型，它们将与MAGP-1基因敲除小鼠杂交以 使两个MAGP缺失的小鼠评估MAGP是否存在重叠 关键功能。

DESCRIPTION (Applicant's Abstract): Microfibril-associated glycoprotein-2 (MAGP-2) is one of two MAGPs, both of which are integral components of microfibrils associated with elastic fibers. MAGP-2 is shown herein to bind specifically to fibrillin-1 and -2, two well-characterized constituents of extracellular microfibrils that are genetically linked to heritable disorders of elastic fibers known as the Marfan syndrome and congenital contractural arachnodactyly, respectively. MAGP-2 also binds MAGP- 1. In this proposal, the function of MAGP-2 within the microfibril will be examined. MAGP-2 binding sites on both fibrillin-1 and MAGP-1 will be localized, as will determinants within MAGP-2 responsible for these. The spatial and temporal pattern of MAGP-2 gene expression in the developing mouse will be determined, and coexpression/colocalization with other major elastic fiber components will be assessed. MAGP-2 expression in the MAGP-1 knockout mouse will also be investigated. A mouse harboring a targeted disruption of the MAGP-2 gene will be generated and assessed for developmental abnormalities. Microfibrils in MAGP-2 -/- mice will be studied at the ultrastructural level. If the mouse dies during embryonic development, primary fibroblast cultures will be derived from MAGP-2 -/- lungs and used to study the role of MAGP-2 in microfibril assembly in vitro. The role of MAGP-2 in lung branching morphogenesis will also be studied in knockouts should their lungs develop abnormally. If the MAGP-2 -/- mice lack an overt phenotype, they will be bred with MAGP-1 knockout mice to make mice lacking both MAGPs to assess whether the MAGPs have overlapping yet critical functions.