Structural investigation of focal adhesion formation and disassembly

描述(由申请人提供)：细胞迁移由焦点粘连(FA)的交替形成和分解促进；我们的长期目标是了解管理这些动态事件的机制。在FA的形成中，多个黏附分子集中在一个小区域，其中复杂的蛋白质相互作用具有高度特异性，尽管一些结合亲和力相对较弱。因为蛋白质含量相对较高 在FA位点的浓度、结合亲和力起着关键作用，而磷酸化介导 结合亲和力的变化可以完全改变复杂网络中相互作用的平衡。因此，为了阐明局部粘连形成和分解的调控机制，我们必须详细了解FA及其结合伙伴之间的结构和生物物理相互作用，并确定磷酸化如何影响这些相互作用；这是该项目的重点。具体地说，我们将研究paxlin家族蛋白及其在FA中的结合伙伴。Paxlin及其相关蛋白是FA的关键蛋白；作为支架蛋白，它们利用其N-末端的LD基序与其他FA分子相互作用。一组主要的LD结合伙伴包括FAK的焦点黏附靶向(FAT)结构域和其他FA蛋白的脂肪样结构域。尽管类脂肪结构域具有相似的结构，但它们与Paxlin家族蛋白的LD基序的相互作用在许多方面都不同。这些差异为剖析FA形成和拆解过程中复杂相互作用的动力学提供了一个很好的起点。这项研究还将有助于设计针对FA中特异结合事件的抑制剂，以调节FA的动力学。

DESCRIPTION (provided by applicant): Cell migration is promoted by the alternating formation and disassembly of focal adhesions (FAs); our long-term goal is to understand the mechanisms that govern these dynamic events. In FA formation, multiple adhesion molecules are concentrated in a small area in which complex protein interactions are highly specific, although some of the binding affinities are relatively weak. Because of the relatively high protein concentration at the FA locus, binding affinity plays a critical role, and phosphorylation-mediated changes in binding affinity can completely alter the balance of interactions within the complex network. Therefore, to elucidate the mechanism that regulates the formation and disassembly of focal adhesions, we must understand in detail the structural and biophysical interactions within FAs and their binding partners and determine how phosphorylation affects these interactions; this is the focus of the project. Specifically, we will study paxillin family proteins and their biding partners in FAs. Paxillin and its related proteins are key players in FAs; as scaffold proteins, they use their N-terminal LD motifs to interact with other FA molecules. One major group of LD binding partners comprises the focal adhesion targeting (FAT) domain of FAK and the FAT-like domains of other FA proteins. Although the FAT-like domains have similar structures, their interactions with the LD motifs of paxillin family proteins differ in many ways. These differences offer an opportune starting point to dissect the dynamics of the complex interactions in FA formation and disassembly. This study will also aid in the design of inhibitors that target specifi binding events in FAs in order to mediate FA dynamics.