Function of Desmoglein 1/Pemphigus Foliaceus Antigen

桥粒芯糖蛋白 1/天疱疮叶状疱疹抗原的功能

• 批准号: 7114301
• 负责人: Kathleen Janee Green
• 金额: $ 30.33万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 2007-09-13
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7114301
• 关键词: apoptosis; autoantibody; autoantigens; cadherins; cell adhesion; cell adhesion molecules; cell line; clinical research; cysteine endopeptidases; cytoskeletal proteins; fluorescent dye /probe; genetically modified animals; human tissue; intercellular connection; intermediate filaments; keratinocyte; laboratory mouse; pathologic process; pemphigus; protein protein interaction; protein structure function; tissue /cell culture; ultraviolet radiation

DESCRIPTION (provided by applicant): Desmogleins are members of the cadherin superfamily of cell adhesion molecules. Along with desmocollins (Dscs), desmogleins (Dsgs) make up the adhesive core of the desmosome through their extracellular domains, and anchor intermediate filaments to the plasma membrane through interactions between their cytoplasmic domains and armadillo/plakin proteins. Autoantibodies directed against desmogleins are causative in the blistering diseases known as pemphigus; however, the molecular mechanism underlying pathogenesis in pemphigus is poorly understood. Furthermore, there are three Dsg genes and three Dsc genes, expressed in a differentiation-dependent manner in the epidermis, and it is unclear why multiple genes are required. To understand the underlying basis of human autoimmune and inherited disorders targeting the desmogleins, it will be crucial to determine the functions of desmosomal cadherins as well as how the adhesive complex is assembled, maintained and regulated. Our aims for the next funding period are: 1) To determine the molecular basis of desmosomal cadherin-mediated adhesion and pairing preferences for Dscs and Dsgs by using a tetracycline-regulatable system in which adhesive function can be reconstituted in L929 cells, and to develop this system into a test for the pathogenic activity of pemphigus antibodies, 2) To determine how Dsgs/Dscs collaborate with armadillo proteins to form distinct, differentiation-specific protein complexes using a combination of in vitro and high resolution structural studies to establish the identity and affinity of desmosomal cadherin-armadillo binding partners, and cellular reconstitution techniques to determine how interactions translate into structurally distinct desmosomes, 3) To determine how desmosomal cadherins and their associated proteins are coordinated spatially and temporally during their assembly into keratinocytes by time lapse analysis of living cells using fluorescently-labeled probes, and 4) To determine the function of Dsg1 and biological significance of Dsg1 as a caspase substrate for keratinocyte adhesion, differentiation and apoptosis by defining UV-dependent Dsg1 processing events that occur in vitro and in cultured keratinocytes and by defining the roles of wild type Dsg1 its cleavage products and cleavage resistant forms during differentiation in cultured human keratinocytes and transgenic mice.

描述(申请人提供)：桥粒蛋白是细胞黏附分子钙粘附素超家族的成员。桥粒蛋白(Desmogleins，DGs)与桥粒蛋白(Desmocollins，DSCs)一起，通过胞外结构域构成桥粒的黏附核心，通过胞质结构域与/Plakin蛋白相互作用，将中间细丝锚定在质膜上。针对桥粒蛋白的自身抗体是天疱疮这种水泡性疾病的病因；然而，天疱疮发病的分子机制尚不清楚。此外，有三个DSG基因和三个DSC基因在表皮中以依赖于分化的方式表达，目前尚不清楚为什么需要多个基因。为了了解针对桥粒蛋白的人类自身免疫和遗传性疾病的潜在基础，确定桥粒钙粘附素的功能以及如何组装、维持和调节黏附复合体将是至关重要的。我们在下一个资金阶段的目标是：1)利用四环素可调节的系统，在L929细胞中重建黏附功能，以确定桥粒钙粘素介导的黏附的分子基础和对DSCs和DGs的配对偏好，并将该系统发展为天疱疮抗体致病活性的测试；2)结合体外和高分辨率结构研究，确定DSC/DSCs如何与蚂蚁蛋白合作形成独特的、分化特异的蛋白质复合体，以建立桥粒钙粘素-黏附分子结合伙伴的身份和亲和力，以及细胞重组技术，以确定相互作用如何转化为结构上不同的桥粒、3)通过使用荧光标记探针对活细胞进行时间推移分析，确定桥粒钙粘附素及其相关蛋白在组装成角质形成细胞过程中如何在空间和时间上进行协调；以及4)通过定义在体外和培养的角质形成细胞中发生的依赖紫外线的DSG1处理事件，以及野生型DSG1及其裂解产物和裂解抗性形式在培养的人角质形成细胞和转基因小鼠分化过程中的作用，确定DSG1作为角质形成细胞黏附、分化和凋亡的半胱氨酸酶底物的功能和生物学意义。