FUNCTION OF DESMOGLEIN1/PEMPHIGUS FOLIACEUS ANTIGEN

患有发疱性疾病落叶型天疱疮（PF）的患者 抗原靶点为跨膜的循环自身抗体 桥粒钙粘蛋白称为桥粒芯糖蛋白1（Dsg1）。 已经 假设PF IgG可能通过以下方式直接抑制细胞粘附： 直接结合Dsg1抗体的细胞外结构域 引起PF水泡，Dsg1在粘附中的作用也没有被 研究了 在上一个供资期间， 已经确定了PF抗体所针对的特异性表位， 旨在确定PF抗体与这些抗体的结合， 表位依赖于它们的正确构象， 证明抗Dsg1抗体在疾病中是致病性的。 然而，抗Dsg1导致 棘层松解是未知的。 阐明这一进程将取决于 首先了解桥粒钙粘蛋白粘附复合物 组装、维护和管理。 我们未来五年的目标 年：1。定义Dsg1和其他 成纤维细胞桥粒钙粘蛋白与细胞间粘附 重建系统，并测试假设，细胞骨架 桥粒斑蛋白是桥粒钙粘蛋白介导的 粘连 2.为了建立桥粒的结构 粘附界面的钙粘蛋白胞外区 通过交联角质形成细胞表面分子的桥粒 并通过肽测序分析交联。 3. 探讨 不寻常的6：1的基础和生物学意义 由斑珠蛋白：Dsg1复合物表现出的化学计量， 斑珠蛋白：Dsg1相互作用是否受 Dsg1胞质尾的磷酸化，和4.审查 异位表达Dsg1或显性表达的结果 阴性斑珠蛋白突变体对粘附、分层和 器官型筏培养中角质形成细胞分化。

Patients with the blistering disease pemphigus foliaceus (PF) have circulating autoantibodies whose antigenic target is a transmembrane desmosomal cadherin called desmoglein 1 (Dsg1). It has been hypothesized that PF IgG might directly inhibit cell adhesion by binding to the extracellular domain of Dsg1 antibodies directly cause PF blisters, nor had Dsg1's role in adhesion been investigated. Over the last funding period substantial progress has been made to define specific epitopes against which PF antibodies are directed, to determine that binding of PF antibodies to these epitopes is dependent on their correct conformation and to demonstrate that anti-Dsg1 antibodies are pathogenic in the disease. However, the precise mechanism by which anti-Dsg1 results in acantholysis is not known. Elucidating this process will depend on first understanding how the desmosomal cadherin adhesive complex is assembled, maintained and regulated. Our aims for the next five years are: 1. To define the contribution of Dsg1 and other desmosomal cadherins to cell-cell adhesion in a fibroblast reconstitution system and to test the hypothesis that the cytoskeletal linker, desmoplakin, is required for desmosomal cadherin-mediated adhesion. 2. To establish the organization of the desmosomal cadherin extracellular domains at the adhesive interface of desmosomes by cross-linking keratinocyte cell surface molecules and analyzing cross-links by peptide sequencing. 3. To investigate the basis and biological significance of the unusual 6:1 stoichiometry exhibited by the plakoglobin:Dsg1 complex and whether plakoglobin:Dsg1 interactions are regulated by phosphorylation of the Dsg1 cytoplasmic tail, and 4. To examine the consequences of ectopically expressing Dsg1 or dominant negative plakoglobin mutants on adhesion, stratification and keratinocyte differention in organotypic raft cultures.