Molecular mechanism of E-Cadherin mediated mechano-sensing

E-钙粘蛋白介导的机械传感的分子机制

• 批准号: 414057127
• 负责人: Professorin Dr. Frauke Gräter
• 金额: --
• 依托单位: Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/414057127?language=en
• 关键词: Molecular; mechanism; Cadherin; mediated; mechano

E-cadherin provides the mechanical inter-cellular link at adherens junctions. It serves as a dynamic hub that translates cell-cell adhesion forces into biochemical downstream processes, the molecular mechanisms of which remain to be explored. The intrinsically disordered cytoplasmic tail of E-cadherin binds to p120, -catenin, and indirectly to -catenin and actin. Mechanical force leads to a displacement of p120 and -catenin from the E-cadherin tail, processes which are critical for tension-regulated cell division. The proposed work aims at unravelling the mechanisms underlying these E-cadherin mechano-sensing functions, using atomistic simulations and bioinformatics analyses. We hypothesize that the E-cadherin tail uncoils and straightens under the tensile force of adherens junctions, and thereby reorients the attached elongated armadillo-repeat catenin molecules along the force direction, which in turn directly affects the E-cadherin/catenin interactions. We will test this hypothesis by constructing atomistically resolved models of the E-cadherin transmembrane and cytosolic domains embedded into the membrane, and successively adding the catenin binding partners to the disordered E-cadherin tail. We will then subject these structures to Molecular Dynamics simulations in presence and absence of tensile forces, mimicking the adherens junction conditions. Given the comparably short E-cadherin cytosolic tail and the rotational constraint the mechanical force has on the bound catenins and their binding interfaces, we expect the force-dependent dynamics obtained from simulations to show substantial changes in the cadherin/catenin interactions. Such changes could manifest themselves as an altered p120-membrane interaction, steric hindrance among the two adjacently bound p120 and -catenin molecules, or a decrease of interfacial interactions at the E-cadherin/catenin binding sites. We will additionally also address the effect of E-cadherin phosphorylation on these processes by additional simulations with modified phosphorylation states. Finally, we will ask whether the observed mechano-sensing mechanisms are similarly at play among the large families of conventional cadherins and catenins, by large-scale sequence alignments and coevolution analysis.Our work programme will provide unprecedented insights into the force response of cadherin/catenin complexes and will give mechanistic explanations for their mechano-sensing role. The outcomes of our simulations will be directly tested by mutagenesis experiments in collaboration, and will also help to interpret and guide experiments on the more complex cellular and tissue levels undertaken within the SPP.

E-钙粘蛋白在粘附连接处提供细胞间的机械连接。它作为一个动态的枢纽，将细胞-细胞粘附力转化为生化下游过程，其分子机制仍有待探索。E-钙粘蛋白的本质上无序的胞质尾区与p120、-连环蛋白结合，并间接与-连环蛋白和肌动蛋白结合。机械力导致p120和-catenin从E-钙粘蛋白尾部的位移，这是张力调节细胞分裂的关键过程。拟议的工作旨在解开这些E-cadherin机械传感功能的机制，使用原子模拟和生物信息学分析。我们假设，E-钙粘蛋白尾部解卷和拉直的粘附连接的张力下，从而重新定向连接拉长的犰狳重复链蛋白分子沿着力的方向，这反过来又直接影响E-钙粘蛋白/链蛋白的相互作用。我们将通过构建嵌入膜中的E-钙粘蛋白跨膜和胞质结构域的原子分辨模型，并连续将连环蛋白结合伴侣添加到无序的E-钙粘蛋白尾部来测试这一假设。然后，我们将在存在和不存在张力的情况下对这些结构进行分子动力学模拟，模拟粘附连接条件。鉴于短的E-钙粘蛋白胞质尾部和旋转约束的机械力上的绑定的连环蛋白和它们的结合界面，我们预计从模拟获得的力依赖的动力学显示钙粘蛋白/连环蛋白的相互作用的实质性变化。这种变化可以表现为改变p120-膜相互作用，空间位阻之间的两个相邻的结合p120和-连环蛋白分子，或减少界面相互作用的E-钙粘蛋白/连环蛋白结合位点。此外，我们还将通过修改磷酸化状态的额外模拟来解决E-钙粘蛋白磷酸化对这些过程的影响。最后，我们将询问所观察到的机械感应机制是否同样在发挥作用的大家庭之间的传统钙粘蛋白和连环蛋白，通过大规模的序列比对和coevolutionsanalysis.Our工作计划将提供前所未有的洞察力的钙粘蛋白/连环蛋白复合物的力响应，并会给他们的机械感应作用的机制解释。我们的模拟结果将直接通过诱变实验进行测试，也将有助于解释和指导SPP内进行的更复杂的细胞和组织水平的实验。