How tensins transform focal adhesions into fibrillar adhesions and phase separate to form new adhesion signalling hubs.

张力蛋白如何将粘着斑转化为纤维状粘连并相分离以形成新的粘连信号中枢。

• 批准号: BB/Y004841/1
• 负责人: Christoph Ballestrem
• 金额: $ 76.98万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FY004841%2F1
• 关键词: How; tensins; transform; focal; adhesions

Tissues in our body are made up of cells and surrounding fibrillar material, the extracellular matrix or ECM. The cells attach to, sense and reorganise the ECM, an ability which is particularly important during the development of organisms, in diseases and in regeneration processes, which all require specific cellular responses to changing ECM environments. Cellular responses include changes in their ability to move (e.g. closing of wounds), changes in cell growth, and also in synthesising new or reshaping their old ECM environment. Many studies have focused on how cells sense the ECM, but we are still far from understanding how this information is translated into signals that promote specific cellular responses. Understanding this process is critically important if we want to get a step closer to treating the roots of diseases and promoting regeneration and recovery. Cells sense their ECM environment by grabbing and pulling the neighbouring extracellular fibrillar material using proteins called integrins, which extend across the cell surface from inside to outside. Integrins both bind to the ECM externally and to proteins inside the cells. These proteins couple integrins to the actin cytoskeleton, a contractile network of intracellular fibres, which upon reorganisation induces pulling forces and cell movement. Our previous results show that two proteins that couple integrins to actin, called talin and vinculin, are central to sensing environmental changes. Recently we have shown that the association of talin with other proteins, tensins, is critical for ECM reorganisation. We now have further data showing that a gradual increase in the concentration of tensins in specific areas in cells can lead them to form little droplets or condensates. We hypothesise that these tensin condensates can also attract other proteins that have a critical role in the regulation of cell adhesion and cell migration. Testing this hypothesis requires detailed information on how proteins bind to each other and how these impact on specific cellular functions. To overcome this gap in our understanding, we propose a joint effort of two laboratories that have vast expertise in the field of cell adhesion regulation but apply very different research methods. The Barsukov laboratory determines details of a protein structure, which is critical for the understanding how proteins bind to each other. Structural details help to design small changes (mutations) in proteins with the aim of experimentally blocking specific proteins interactions. The Ballestrem laboratory has developed powerful methods in cell biology and microscopy that monitor protein interactions in cells and investigate what role these interactions play in determining cell behaviour in the face of changing ECM environments. Both teams have already worked successfully together and revealed essential mechanisms that control cell-matrix sensing and ECM organisation.The proposed research aims to understand (i) how tensins interact with talin and what role this interaction has in enriching tensins in cell-matrix adhesion sites that are involved in ECM reorganisation; (ii) how tensins condense to droplets that can attract other proteins to form molecular reservoirs that regulate cell adhesion and migration; (iii) how tensin binding to integrins is regulated and how this affects the binding strength of integrins to the ECM. Ultimately, the knowledge gained will open a pathway to the development of new ways to prevent diseases (e.g. cancer, fibrosis) and promote regeneration (wound healing).

我们体内的组织由细胞和周围的纤维材料，细胞外基质或ECM组成。细胞附着并重新组织ECM，在生物体的发展，疾病和再生过程中尤其重要的能力，这些能力都需要对不断变化的ECM环境的特定细胞反应。细胞反应包括其运动能力（例如伤口关闭），细胞生长的变化以及合成新的或重塑其旧ECM环境的变化。许多研究集中在细胞如何感知ECM上，但是我们仍然远非了解该信息如何转化为促进特定细胞反应的信号。如果我们想更接近治疗疾病根源并促进再生和恢复，那么了解这一过程至关重要。细胞通过使用称为整合素的蛋白质抓住和拉动相邻的细胞外纤维材料来感知其ECM环境，从而从内部到外部延伸到细胞表面。整联蛋白都与外部和细胞内的蛋白质结合。这些蛋白质将整联蛋白与肌动蛋白细胞骨架（一个收缩的细胞内纤维网络）息息，在重组后，它们会诱导拉力和细胞运动。我们先前的结果表明，将两种整合蛋白与肌动蛋白（称为Talin和Vinculin）伴侣的蛋白质是感应环境变化的核心。最近，我们表明，塔林与其他蛋白质Tensin的关联对于ECM重组至关重要。现在，我们有进一步的数据表明，细胞中特定区域的tensin浓度逐渐增加可以导致它们形成小滴或冷凝水。我们假设这些张力蛋白冷凝物还可以吸引其他在细胞粘附和细胞迁移调节中具有关键作用的蛋白质。检验该假设需要有关蛋白质如何相互结合以及这些对特定细胞功能的影响的详细信息。为了克服这一差距，我们提出了两个实验室的共同努力，这些实验室在细胞粘附调节领域具有广泛的专业知识，但采用了截然不同的研究方法。 Barsukov实验室确定了蛋白质结构的细节，这对于了解蛋白质如何相互结合至关重要。结构细节有助于设计蛋白质中的小变化（突变），以实验阻止特定蛋白质相互作用。 Ballestrem实验室在细胞生物学和显微镜中开发了强大的方法，该方法可以监测细胞中的蛋白质相互作用，并研究这些相互作用在面对ECM环境的情况下确定细胞行为方面的作用。这两个团队都已经成功地共同努力，并揭示了控制细胞基质传感和ECM组织的基本机制。拟议的研究旨在了解（i）tensins如何与塔林相互作用以及这种相互作用在富集tensins in Cell-matrix粘附位点富集的作用，这些作用涉及ECM重新组织； （ii）如何凝结与可以吸引其他蛋白质形成调节细胞粘附和迁移的分子储层的液滴； （iii）如何调节tensin与整联蛋白的结合以及这如何影响整联蛋白与ECM的结合强度。最终，获得的知识将为预防疾病（例如癌症，纤维化）的新方法开辟一条途径，并促进再生（伤口愈合）。