Mechanisms of septin assembly that shape cellular function

塑造细胞功能的隔膜组装机制

• 批准号: 10551563
• 负责人: MICHAEL A MCMURRAY
• 金额: $ 37.52万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2027-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10551563
• 关键词: Address; Behavior; Biochemistry; Biology; Cell physiology; Cellular biology; Complex; Cytoskeletal Filaments; Cytoskeletal Proteins; Diffusion; Disease; Eukaryotic Cell; Filament; Gametogenesis; Genes; Genetic; Genetic Transcription; Individual; Knowledge; Mediating; Modeling; Molecular; Molecular Chaperones; Molecular Conformation; Mutation; Nature; Organism; Pathway interactions; Phenotype; Positioning Attribute; Property; Protein Complex Subunit; Proteins; Research; Rod; Saccharomycetales; Shapes; Specificity; Textbooks; Translating; Translations; Work; Yeasts; cell assembly; insight; protein complex; tool

PROJECT SUMMARY Most cellular functions are carried out by multisubunit protein complexes. Transcribe and translate as much as you want, but odds are if your protein doesn’t assemble properly with other proteins, the gene might as well be off. As the final step in expression of most genes, protein complex assembly is hugely understudied, and it has only recently become clear that the textbook model of diffusion-limited collisions between individual molecules is inadequate. Septin proteins are found as cytoskeletal filaments in many eukaryotic cells and participate in a wide variety of cellular functions. The building blocks of septin filaments are rod-shaped septin complexes composed of distinct septin subunits. Multiple septins “compete” to occupy the same position in, and confer specialized properties to, septin complexes, but it is not fully understood how specific subunits are “chosen” to assemble the functionally appropriate complexes. How individual septins occupy specific positions within complexes is one of the oldest questions in septin biology. Disease-causing septin mutations highlight the importance of answering this question. Our lab is among the leaders in this field and in the next five years we want to use the powerful tools we have developed in budding yeast to address specific knowledge gaps. For other cytoskeletal proteins, achieving the conformation competent for complex assembly requires help from molecular chaperones. How does chaperone-assisted de novo septin folding fit into the pathway of septin complex assembly? Our recent work established the step-wise pathway of septin hetero-octamer assembly, and identified septin-interacting chaperones that engage a septin-septin interaction interface and are necessary for efficient septin folding. We will use a combination of genetics, cell biology and biochemistry to determine how chaperone action sets the stage for septin-septin encounters during complex assembly. Recent studies show that assembly of many complexes occurs co-translationally, and we find chaperone requirements for efficient septin translation. To what extent is septin complex assembly co-translational? We will investigate septin- chaperone and septin-septin interactions in the context of active translation. We previously identified key residues in septin-septin interaction interfaces that mediate “partner recognition” during assembly and dictate the subunit composition within complexes. An enduring mystery is how the two subunits at the “ends” of yeast septin hetero-octamers always match. How do allosteric conformational changes across septin-septin interaction interfaces direct the specificity of septin complex subunit composition? We will determine the mechanistic basis of this phenomenon and determine the phenotypic consequences of inappropriate “mixing” of septin subunits within complexes. Finally, it is not known how, once made, a septin complex is remodeled to incorporate new subunits during cellular differentiation. We will determine the molecular mechanism by which yeast septin complexes are remodeling during gametogenesis. These studies will provide valuable insights into how cells assemble and modify septin complexes, with broader implications for multisubunit assembly in general.

项目摘要 大多数细胞功能是由多亚基蛋白质复合物完成的。尽可能多地转录和翻译 但如果你的蛋白质不能与其他蛋白质正确组装，基因也可能是 关闭.作为大多数基因表达的最后一步，蛋白质复合物组装的研究非常不足， 直到最近才变得清楚，单个分子之间的扩散限制碰撞的教科书模型 是不够的。Septin蛋白在许多真核细胞中作为细胞骨架丝被发现，并参与细胞的增殖和分化。 各种各样的细胞功能。Septin丝的结构单元是棒状Septin复合物 由不同的隔蛋白亚基组成。多个septins“竞争”占据相同的位置，并赋予 septin复合物的特殊性质，但尚未完全理解如何“选择”特定的亚基， 组装功能上合适的复合物。单个分隔符如何占据内部的特定位置 复合物是Septin生物学中最古老的问题之一。引起疾病的septin突变突出了 回答这个问题的重要性。我们的实验室是这一领域的领导者之一，在未来五年内， 我想使用我们在芽殖酵母中开发的强大工具来解决特定的知识缺口。为 其他细胞骨架蛋白，实现复杂组装的构象能力需要帮助， 分子伴侣分子伴侣辅助的Septin从头折叠如何适应Septin的途径 复杂的装配？我们最近的工作建立了septin异源八聚体组装的分步途径， 鉴定的胞隔蛋白相互作用分子伴侣，其接合胞隔蛋白-胞隔蛋白相互作用界面，并且对于 有效的隔蛋白折叠。我们将结合遗传学、细胞生物学和生物化学来确定 伴侣作用为septin-septin在复杂组装过程中相遇奠定了基础。最近的研究表明 许多复合物的组装是协同发生的，我们发现， 分隔符翻译。septin复合体组装在多大程度上是共翻译的？我们会调查赛普丁- 分子伴侣和septin-septin相互作用的背景下，主动翻译。我们之前发现 septin-septin相互作用界面中的残基，其在组装过程中介导“伴侣识别”，并决定 复合物中的亚基组成。一个持久的谜团是酵母“末端”的两个亚基 Septin异八聚体总是匹配的。septin-septin相互作用如何改变变构构象 接口直接的特异性septin复合物亚基组成？我们将确定 并确定septin亚基不适当“混合”的表型后果 在复合体中。最后，尚不清楚一旦制成，septin复合物如何被改造以并入新的 细胞分化过程中的亚基。我们将确定酵母Septin 复合体在配子发生过程中重塑。这些研究将提供有价值的见解，细胞如何 组装和修饰septin复合物，一般多亚基组装具有更广泛的意义。