Deconvoluting the Vascular Adhesome

摘要 以整合素为基础的粘连是血液和血管细胞功能的核心。这个 粘连的非均质性及其动态演化为研究其细微结构提供了复杂的手段 组合、组装和拆卸。我们的研究表明，两者之间的过渡 黏附原型是由与纽蛋白竞争的简单的二元分子开关控制的 以及MRL家族成员Riam或lamellipdin(LPD)从结合位点上的置换 在塔林的杆状区域。此外，我们还开发了成像mrl蛋白复合体的方法。 与整合素和Talin(麻省理工学院复合体)结合，显示它形成了“粘性手指”的尖端， 感觉基质蛋白密度和底物物理状态的突起 间充质细胞迁移。间充质细胞迁移。我们假设麻省理工学院 Complex代表了许多不同的模块中的一个，这些模块对整体 基于整合素的粘连的结构和功能。这表明了一个范例，即 整合素粘附性可以被分析为这些模块的动态组装，这些模块在 进入粘连。这一概念使我们能够提出一种新的研究方法 通过开发方法来纯化整合素连接前形成的每个模块的粘连。为了测试 在这个范例中，我们建议提纯4个这样的模块，并针对a)存在的每个模块进行表征 塔林激活的整合素b)表征其蛋白质组成。C)建立其生物化学 拓扑和规则d)将其在活细胞中可视化并e)评估其功能 实验将以三种方式产生粘附场的基础数据：a)整合素 ADHEDEY将被重新解释为模块化组件的概要；每个组件都有自己的组件 具体的构成。B)功能研究将确定新的血液和血管调节剂 可作为治疗靶点的细胞黏附和信号传递c)完整的定义 每个模块的蛋白质组成将作为公共资源用于分析 基于整合素的粘连，并将为未来的研究提供假设，以了解 对每个模块的组装及其功能输出进行调节。

Summary Integrin-based adhesions are central to the functions of blood and vascular cells. The heterogeneity of adhesions and their dynamic evolution has complicated efforts to study their fine composition, assembly, and disassembly. Our studies have shown that a transition between two adhesion archetypes is controlled by a simple binary molecular switch of vinculin competition with and displacement of RIAM or lamellipodin(Lpd), members of the MRL family, from binding sites on talin's rod domain. Furthermore, we developed methods to image the complex of MRL proteins with integrins and talin (MIT complex) and showed that it formed the tips of “sticky fingers,” cellular protrusions that sense the density of matrix proteins and physical state of the substrate during mesenchymal cell migration. mesenchymal cell migration. We hypothesize that the MIT complex represents one among many distinct modules that contribute to the overall structure and function of integrin- based adhesions. This suggests the paradigm that the integrin adhesome can be analyzed as a dynamic assembly of these modules, which form prior to entry into the adhesions. This concept has enabled us to propose a new approach to studying adhesions by developing methods to purify each module formed prior to integrin ligation. To test this paradigm, we propose to purify 4 such modules and to characterize each for a) the presence of talin-activated integrins b) characterize its protein composition. c) establish its biochemical topology and regulation d) visualize it in living cells and e) evaluate its functions The proposed experiments will generate foundational data for the adhesion field in three ways: a) the integrin adhesome will be re- interpreted as a compendium of modular components; each with its own specific composition. b) The functional studies will identify new regulators of blood and vascular cell adhesion and signaling that may be exploitable as therapeutic targets c) A complete definition of the protein composition of each module will serve as a public resource for the analysis of integrin-based adhesions and will be hypothesis-generating for future studies to understand the regulation of assembly of each module and its functional outputs.