The physics and structural biology of supramolecular protein self-assembly in meiotic chromosome synapsis

减数分裂染色体突触中超分子蛋白自组装的物理和结构生物学

• 批准号: 2894984
• 金额: --
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2894984
• 关键词: physics; structural; biology; supramolecular; protein

One of the largest protein structures in the cell is the synaptonemal complex (SC), which synapses together homologous chromosomes to facilitate their recombination during meiosis. As such, the SC is essential for fertility, and its defects lead to human infertility, recurrent miscarriage, and aneuploidy. The zipper-like structure of the SC is up to 25 micrometres in length, and forms through self-assembly of its eight coiled-coil protein constituents. This occurs by formation of three distinct architectural self-assembled units. Firstly, SYCP3 assembles into a paracrystalline array that loops and compacts chromatin within linear chromosome axes (Syrjanen et al 2014). Then, SYCP1 forms a recursive lattice-like array that binds together homologous chromosome with a 100 nm separation (Dunce et al 2018). Finally, SYCE2-TEX12 undergoes hierarchical assembly from a 2:2 complex through a 4:4 structure into micrometre-length fibres, which resemble intermediate filaments, and provide structural support for SC growth along the chromosome length (Dunce et al 2021).This PhD project aims to uncover the physics of how the SC's coiled-coil protein components self-assemble into its principal architectural units. We will use computational methods to design mutants and re-engineer proteins with altered self-assembly characteristics, such as rigidity, repeating units, width and length, to probe the biology and widen the range of SC-related biomaterials. We will test these biochemically, determining structures and assembly dynamics by biophysics and structural biology. Our findings will lead to experimentally-determined structures of large-scale macromolecular assemblies and mathematical models of dynamic coiled-coil protein self-assembly. The outcomes of this integrated experimental and computational project are wide-reaching. Firstly, high-resolution structures of engineered protein assemblies will provide unprecedented understanding of the molecular structure of the SC, overcoming the current technical limitations of studying native SC proteins. These biological findings will be tested through the generation of mouse mutants by our collaborators at the MRC Human Genetics Unit (https://www.ed.ac.uk/mrc-human-genetics-unit). Secondly, it will establish a physical basis for supramolecular self-assembly of coiled-coil proteins that will be applicable to a wide range of biological systems. Finally, it will determine how we can manipulate the unique biochemical structures formed by SC proteins for research and for use as biomaterials.This project will involve a wide range of biochemical, biophysical, structural biology, computational and theoretical modelling methods. The laboratory-based methods include recombinant protein expression and purification, light and X-ray scattering, X-ray crystallography, cryo-EM and cryo-ET, which will include data collection at the Diamond Light Source synchrotron facility (www.diamond.ac.uk). Computational and theoretical methods include AI-based structural modelling, molecular dynamics, and building and simulating mathematical models of bio-assemblies, which will be performed in collaboration with the Institute for Condensed Matter and Complex Systems (https://www.ph.ed.ac.uk/icmcs).This PhD provides an excellent opportunity for a student with a biochemical/structural biology, computational or physics background to engage in cutting-edge research into the physics of life.

细胞中最大的蛋白质结构之一是突触复合物（SC），该复合物将突触融合在一起同源染色体，以促进其在减数分裂过程中的重组。因此，SC对于生育至关重要，其缺陷导致人类不育症，反复流产和非整倍性。 SC的拉链状结构的长度高达25微米，并通过其八个盘绕蛋白蛋白成分的自组装形成。这是通过形成三个不同建筑自组装单元的形成而发生的。首先，Sycp3组装成二晶阵列，该阵列在线性染色体轴内循环并压实染色质（Syrjanen等人，2014年）。然后，SYCP1形成一个递归晶格样阵列，该阵列将同源染色体结合在一起，与100 nm的分离（Dunce等人，2018年）。 Finally, SYCE2-TEX12 undergoes hierarchical assembly from a 2:2 complex through a 4:4 structure into micrometre-length fibres, which resemble intermediate filaments, and provide structural support for SC growth along the chromosome length (Dunce et al 2021).This PhD project aims to uncover the physics of how the SC's coiled-coil protein components self-assemble into its principal architectural units.我们将使用计算方法来设计具有改变自组装特征（例如刚度，重复单元，宽度和长度）的突变体和重新工程蛋白，以探测生物学并扩大与SC相关的生物材料的范围。我们将通过生物物理学和结构生物学来确定结构和组装动力学。我们的发现将导致大规模大分子组件的实验确定结构以及动态盘绕蛋白自组装的数学模型。这个集成的实验和计算项目的结果是广泛的。首先，工程蛋白质组件的高分辨率结构将对SC的分子结构提供前所未有的理解，从而克服了研究天然SC蛋白的当前技术局限性。这些生物学发现将通过我们的合作者在MRC人类遗传学单元（https://www.ed.ac.ac.uk/mrc-human-genetics-unit）的生成小鼠突变体的产生来测试。其次，它将为盘绕蛋白的超分子自组装建立物理基础，该蛋白适用于广泛的生物系统。最后，它将决定我们如何操纵由SC蛋白进行研究并用作生物材料的独特生化结构。该项目将涉及广泛的生化，生物物理，结构生物学，计算和理论模型方法。基于实验室的方法包括重组蛋白表达和纯化，光和X射线散射，X射线晶体学，冷冻EM和冷冻-ET，其中包括Diamond Light Source Synchrotron设施（www.diamond.ac.uk）的数据收集。 Computational and theoretical methods include AI-based structural modelling, molecular dynamics, and building and simulating mathematical models of bio-assemblies, which will be performed in collaboration with the Institute for Condensed Matter and Complex Systems (https://www.ph.ed.ac.uk/icmcs).This PhD provides an excellent opportunity for a student with a biochemical/structural biology, computational or physics background从事生命物理学​​的最先进的研究。