BEALS SYNDROME & ITS RELATIONSHIP TO MARFAN SYNDROME

比尔斯综合症

• 批准号: 2081038
• 负责人: CHERYL L MASLEN
• 金额: $ 11.71万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-15 至 1999-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2081038
• 关键词: Marfan syndrome; autosomal dominant trait; calcium binding protein; congenital skeletal disorder; epidermal growth factor; epitope mapping; extracellular matrix proteins; gene mutation; genetic techniques; human subject; immunoelectron microscopy; immunofluorescence technique; linkage mapping; monoclonal antibody; nucleic acid sequence; phenotype; protein sequence

Beals syndrome, also known as congenital contractural arachnodactyly (CCA), is an inherited disorder thought to be due to a defect in a connective tissue component. Affected individuals display a Marfanoid habitus, joint contractures, ear deformities and occasional cardiovascular defects. CCA has been presumed to be allelic to the Marfan syndrome (MfS) because of striking phenotypic similarities. However, recent linkage data indicates that a partially characterized gene on chromosome 5 is responsible for CCA rather than the fibrillin gene on chromosome 15 which is defective in MfS. The sequence of the putative CCA gene shows a high degree of identity with the fibrillin gene suggesting that the two proteins are related. However, the CCA gene product has not yet been isolated, nor is anything known about its tissue distribution or physiological function. Furthermore, no mutations have been identified in any CCA patient. The long-term objectives of this study are to determine the pathogenesis of CCA and to clarify its relationship to MfS. This involves defining and comparing the roles of the proteins involved and understanding the consequences of mutations in relationship to the disease phenotypes. The range and nature of mutations giving rise to CCA will be determined in a group of CCA patients using Chemical Mismatch Cleavage analysis. The consequences of those mutations to the structure and function of the defective protein will be determined by comparative analysis of the properties of normal and mutated domains. From a comparison of the deduced amino acid sequence of the CCA gene with fibrillin, dissimilar regions will be selected to make synthetic peptides specific for the CCA gene product. These will be used to prepare antisera and monoclonal antibodies for protein characterization. Immunofluorescent tissue staining and immunoelectron microscopy will reveal the tissue distribution of the epitope and tissue structures that contain the CCA gene product. The antibodies will also be used to isolate the protein from extracts or proteolytic digests of appropriate tissues or from cell culture medium. Limited protein sequence analysis will confirm that the isolated protein is indeed the CCA gene product. The homologous region between fibrillin and the CCA gene product consists largely of repeated epidermal growth factor precursor (pEGF)-like domains containing predicted calcium binding sites and domains that are homologous to a domain in TGF-beta-1 binding protein. Missense mutations in these domains have been identified in several Marfan patients. Phenotypic similarities between the MfS and CCA suggest that similar mutations may be found in CCA. In addition, fibrillin has a potential SH3 binding domain that is not present in the CCA protein. This strongly implicates this region as a site of protein- protein interaction making it an important distinguishing feature between the two proteins. An expression system in E. coli will be designed to synthesize selected structural domains so that the normal physiological function and the effect of CCA mutations can be studies. Elucidating the structural and functional differences between the CCA protein and fibrillin will help explain the comparative pathogenesis of these diseases and the role of the protein in the development of the human cardiovascular, skeletal and ocular systems.

比尔斯综合征，也称为先天性挛缩性蜘蛛指畸形 (CCA)，是一种遗传性疾病，被认为是由于基因缺陷所致 结缔组织成分。 受影响的个体表现出马方样特征 习惯、关节挛缩、耳朵畸形和偶尔的 心血管缺陷。 CCA 被认为是等位基因 马凡综合征（MfS）由于显着的表型相似性。 然而，最近的关联数据表明，部分特征 5 号染色体上的基因负责 CCA，而不是原纤维蛋白 15 号染色体上的 MfS 基因有缺陷。 的顺序为 推定的 CCA 基因与原纤维蛋白基因表现出高度的同一性 表明这两种蛋白质是相关的。 然而，CCA 基因 产品尚未分离，对其组织也一无所知 分布或生理功能。 此外，没有突变 已在任何 CCA 患者中发现。 本次活动的长期目标 研究的目的是确定 CCA 的发病机制并阐明其 与 MfS 的关系。 这涉及定义和比较以下角色 涉及的蛋白质并了解突变的后果 与疾病表型的关系。 范围和性质 引起 CCA 的突变将在一组 CCA 中确定 患者使用化学错配裂解分析。 的后果 有缺陷的蛋白质的结构和功能的突变 将通过对正常的特性进行比较分析来确定 和突变域。 通过比较推导的氨基酸 CCA 基因与原纤维蛋白的序列，不同的区域将是 选择用于制造针对 CCA 基因产物的合成肽。 这些将用于制备抗血清和单克隆抗体 蛋白质表征。 免疫荧光组织染色和 免疫电子显微镜将揭示组织分布 含有 CCA 基因产物的表位和组织结构。 这 抗体也将用于从提取物或 适当组织或细胞培养基的蛋白水解消化物。 有限的蛋白质序列分析将证实分离的蛋白质 确实是CCA基因的产物。 原纤维蛋白之间的同源区域 CCA基因产物主要由表皮的重复生长组成 包含预测的钙结合的因子前体 (pEGF) 样结构域 与 TGF-β-1 结合域同源的位点和域 蛋白质。 这些结构域中的错义突变已在 几名马凡氏症患者。 MfS 和 CCA 之间的表型相似性 表明在 CCA 中可能发现类似的突变。 此外， 原纤维蛋白具有潜在的 SH3 结合结构域，而该结构域不存在于 CCA 蛋白。 这强烈暗示该区域是蛋白质的位点 蛋白质相互作用使其成为重要的区分特征 两种蛋白质。 大肠杆菌中的表达系统将被设计用于 合成选定的结构域，使正常的生理 可以研究CCA突变的功能和影响。 阐明 CCA 蛋白和 CCA 蛋白之间的结构和功能差异 原纤维蛋白将有助于解释这些疾病的比较发病机制 疾病以及蛋白质在人类发育中的作用 心血管、骨骼和眼部系统。