Deconvoluting the Vascular Adhesome

总结 基于整合素的粘附对血液和血管细胞的功能至关重要。的 粘连的异质性及其动态演变使得研究其精细结构的努力变得复杂。 组合、组装和拆卸。我们的研究表明， 粘附原型由粘着斑蛋白竞争的简单二元分子开关控制， 以及从结合位点置换RIAM或MRL家族成员lamellipodin（Lpd） 在塔林的罗德领地上此外，我们还开发了MRL蛋白复合物的成像方法， 与整合素和talin（MIT复合物），并表明它形成了“粘手指”的尖端，细胞 突起感测基质蛋白的密度和基底的物理状态， 间充质细胞迁移间充质细胞迁移我们假设麻省理工学院 复合体代表了许多不同模块中的一个，这些模块有助于整体 基于整合素粘连的结构和功能。这表明， 整合素粘附体可以作为这些模块的动态组装体来分析，这些模块在整合素粘附体之前形成。 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之前形成的每个模块，测试 这个范例，我们建议纯化4个这样的模块，并表征每个模块的a）存在 talin活化的整联蛋白B）表征其蛋白质组成。（三）建立生物化学 拓扑结构和调控d）在活细胞中可视化它和e）评估其功能 实验将以三种方式产生粘附场的基础数据： 粘附体将被重新解释为模块化组件的纲要;每个组件都有自己的 具体组成。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粘附和信号传导 每个模块的蛋白质组成将作为分析的公共资源， 整合素为基础的粘连，并将为未来的研究假设，以了解 调节每个模块的组装及其功能输出。

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.