Defining the Role of MAGP-2 in Microfibril Assembly

描述（申请人的摘要）：微原纤维相关糖蛋白-2 （MAGP-2）是两个MAGP之一，两者都是 与弹性纤维有关的微纤维。本文显示MAGP-2结合 具体地说，是两种充分表征的组分， 与遗传性疾病有遗传联系的细胞外微纤维 被称为马凡氏综合征和先天性挛缩的弹性纤维 蜘蛛状趾畸形。MAGP-2也结合MAGP- 1。在本提案中， 将检查微纤维内MAGP-2的功能。MAGP-2结合 位点在两个repeatin-1和MAGP-1将被本地化，将决定因素 MAGP-2内部负责这些。MAGP-2的时空分布 将测定发育中小鼠的基因表达， 与其他主要弹性纤维组分的共表达/共定位将是 评估。MAGP-1敲除小鼠中的MAGP-2表达也将被检测。 研究了携带MAGP-2基因的靶向破坏的小鼠将 生成并评估发育异常。微纤维在 将在超微结构水平研究MAGP-2 -/-小鼠。如果老鼠死了 在胚胎发育过程中，原代成纤维细胞培养物将来源于 MAGP-2 -/-肺，并用于研究MAGP-2在微纤维组装中的作用 体外还将研究MAGP-2在肺分支形态发生中的作用。 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敲除小鼠一起繁殖， 使小鼠缺乏这两种MAGP，以评估MAGP是否具有重叠， 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.