Understanding the Biology of Chronic Ulcers: Histological and Molecular Basis...

经典钙粘附素对细胞黏附的分子机制现已在原子水平上被理解。 细节。然而，桥粒钙粘附素的功能基础尚未确定。这位飞行员和 可行性项目的重点是确定桥粒钙粘附素的第一个高分辨率结构 以确定其细胞黏附功能的详细分子基础。钙粘蛋白家族是 以其胞外钙粘素重复结构域(EC1-EC5)为特征。众所周知，这种粘合剂 钙粘附素胞外区的功能依赖于钙离子在细胞外的结合 这些重复结构域导致整个区域的强直化，然而，特定的界面 导致粘连的相互作用还没有被清楚地理解。在这个问题上有了一些启示 最近，本课题组对C-钙粘蛋白胞外区的晶体结构进行了研究。这 结构显示，C-钙粘附素与相对细胞表面的结合很可能发生在 一个细胞上的C-钙粘蛋白的保守色氨酸(Trp2)残基插入疏水口袋， 含有高度保守的R-A-L残基，位于相对细胞上的C-钙粘附素。此外，据指出， 同一细胞表面的C-钙粘附素可能通过类似的机制相互作用以促进分子聚集 从而允许增强细胞之间的粘附性。Trp2残基和疏水结合 Pocket在桥粒钙粘附素中是保守的，因此，似乎很可能桥粒粘附素和 结缔组织可通过同样的机制相互作用。然而，到目前为止，还没有任何 桥粒钙粘附素已被解决。这就引出了我们的假设：粘合剂的结构是什么？ 桥粒钙粘附素的界面？桥粒钙粘附素的黏附界面如何与 有助于桥粒的形成？为了对结构有一些了解 桥粒钙粘附素的胞外结构域，我们已经开始与Angela博士合作 哥伦比亚大学皮肤科克里斯蒂亚诺将细胞外结构域结晶 人类的纤维粘连蛋白。这项先导性和可行性研究的目标是了解详细的分子 钙粘附素在桥粒细胞间连接中的作用机制。 根据指南中的第二类资格，夏皮罗博士有资格成为没有 此前在与发改委相关的研究工作中。他是享誉国际的结构生物学家 已经解析了许多经典钙粘附素的结构。在这项提案中，他将把注意力转向 桥粒钙粘附素，皮肤生物学的核心角色。夏皮罗博士的P&F研究使用了C和D核心。

The molecular mechanism of cell adhesion by classical cadherins is now understood at an atomic level of detail. However, the basis of desmosomal cadherin function has not yet been determined. This Pilot and Feasibility project is focused on determining the first high-resolution structures of desmosomal cadherins in order to determine the detailed molecular.basis of their cell adhesive function. The cadherin family is characterized by their extracellular cadherin repeat domains (EC1-EC5). It is known that the adhesive function of the cadherin extracellular region is dependent upon the binding of calcium ions between each of these repeat domains which leads to the rigidification of the entire region, however, the specific interfaces and interactions responsible for adhesion are not clearly understood. Some light was shed on this issue recently when the crystal structure of the extracellular domain of C-cadherin was solved by our group. This structure revealed that binding between C-cadherins on opposing cell surfaces most likely occurs when a conserved tryptophan (Trp2) residue of a C-cadherin on one cell intercalates into a hydrophobic pocket, containing highly conserved R-A-L residues, of a C-cadherin on an opposing cell. Further, it was noted that C-cadherins on the same cell surface may interact via a similar mechanism to promote molecular clustering thereby allowing for enhanced adhesion between cells. Both the Trp2 residue and the hydrophobic binding pocket are conserved in desmosomal cadherins, therefore, it seems likely that desmogleins and desmocollins may interact via this same mechanism. However, to date no crystal structure for any of the desmosomal cadherins has been solved. This led us to hypothesize: What is the structure of the adhesive interface of a desmosomal cadherin? How do the adhesive interfaces of desmosomal cadherins interact to contribute to the formation of desmosomes? In order to gain some understanding about the structure of the extracellular domain of desmosomal cadherins, we have embarked on a collaborative effort with Dr. Angela Christiano in the Department of Dermatology at Columbia University to crystallize the extracellular domain of human desmogleins. The goal of this Pilot and Feasibility study is to understand the detailed molecular mechanisms of cadherin function in desmosome intercellular junctions. Dr. Shapiro qualifies under eligibility Category #2 in the Guidelines as an Established Investigator with no previous work in research related to the SDRC. He is an internationally renowned structural biologist who has resolved the structure of many classical cadherins. In this proposal, he will turn his attention to the desmosomal cadherins, central players in skin biology. Dr. Shapiro's P&F study utilizes Cores C and D.