Function of Desmoglein 1/Pemphigus Foliaceus Antigen

描述（由申请人提供）：桥粒糖蛋白（Dsgs）和桥粒柯林斯（Dscs）属于钙依赖性粘附分子家族（称为钙粘蛋白），它们共同构成细胞间连接的粘附核心（称为桥粒）。由各种损伤（包括自身免疫抗体、细菌毒素和基因突变）引起的功能失活导致人类皮肤病。不幸的是，我们对这些疾病的分子病因学的理解受到阻碍，缺乏有关桥粒钙粘蛋白组装成粘附能力细胞器的机制和驱动这一过程的分子机制的基本知识。此外，桥粒钙粘蛋白家族成员在复杂组织中的多样性表明，它们可能具有超越其在细胞间粘附中的作用的功能。事实上，我们的工作表明，Dsg1是所需的表皮的形态发生的方式，不需要其粘附域。我们假设桥粒钙粘蛋白在表皮形态发生、分化和重塑过程中同时具有粘附依赖性和非粘附依赖性的功能。为了阐明这些功能和控制它们的分子机制，我们提出：1）通过活细胞成像和生物化学结合细胞外机制的突变分析，确定桥粒钙粘蛋白在活角质形成细胞中的运输机制以及Dsgs和Dscs如何合作建立粘附界面。将产生新型仿生表面作为功能平台，用于评估粘附的要求和致病性天疱疮抗体抑制粘附和下游细胞反应的能力，2）为了确定犰狳蛋白调节桥粒钙粘蛋白组装和与细胞骨架结合的粘附功能的机制，通过蛋白质相互作用的突变分析和使用新型微机械传感器的连接的功能评估，3）利用体外、器官型和小鼠移植模型确定Dsg 1和相关的犰狳蛋白在表皮形态发生中的功能。这些实验有望为Dsg1缺失引起的人类条纹状掌跖角化病提供模型，并将为开发针对桥粒芯蛋白功能的皮肤病治疗方法奠定基础。

DESCRIPTION (provided by applicant): Desmogleins (Dsgs) and desmocollins (Dscs) belong to a family of Ca2+dependent adhesion molecules known as cadherins, which cooperate to make up the adhesive core of intercellular junctions called desmosomes. Functional inactivation by a variety of insults, including autoimmune antibodies, bacterial toxins and gene mutations leads to human skin disease. Unfortunately, our understanding of the molecular etiology of these disorders is hampered by a lack of fundamental knowledge about the mechanisms by which desmosomal cadherins assemble into adhesion-competent organelles and the molecular machinery that drives this process. Further, the diversity of desmosomal cadherin family members within complex tissues, suggests that they may have functions that transcend their roles in intercellular adhesion. Indeed, our work suggests that the Dsg1 is required for the morphogenesis of epidermis in a manner that does not require its adhesive domain. It is our hypothesis that desmosomal cadherins have both adhesion-dependent and -independent functions that are coordinated during epidermal morphogenesis, differentiation and remodeling. Towards elucidating these functions and the molecular machinery that controls them, we propose: 1) To determine the mechanism of desmosomal cadherin trafficking in living keratinocytes and how Dsgs and Dscs cooperate to establish the adhesive interface, through a combination of live cell imaging and biochemistry coupled with mutational analysis of exocytic machinery. Novel biomimetic surfaces will be generated as functional platforms for evaluating requirements for adhesion and the ability of pathogenic pemphigus antibodies to inhibit adhesion and downstream cellular responses, 2) To determine the mechanism by which armadillo proteins regulate desmosomal cadherin assembly and adhesive function in conjunction with the cytoskeleton, by mutational analysis of protein interactions coupled with functional assessment of the linkage using novel micromechanical sensors, 3) To determine the function of Dsg1 and associated armadillo proteins in epidermal morphogenesis using in vitro, organotypic and mouse grafting models. These experiments promise to provide a model for the human disease striate palmoplantar keratoderma caused by loss of Dsg1, and will lay a foundation for developing treatments for skin diseases that target desmoglein function.