The molecular mechanism of membrane protein complex assembly.

膜蛋白复合物组装的分子机制。

• 批准号: 422880195
• 负责人: Dr. Tino Pleiner
• 金额: --
• 依托单位: Division of Biology and Biological Engineering
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/422880195?language=en
• 关键词: molecular; mechanism; membrane; protein; complex

Virtually all cellular processes, from DNA replication to cell signaling, depend on multi-subunit protein complexes. Their assembly must be highly regulated to ensure generation of stoichiometrically defined, functional macromolecules. Any orphan subunits, that are synthesized in excess or remain unassembled, must be recognized and degraded by quality control machinery to prevent non-specific binding and cytotoxic aggregation. One class of proteins for which quaternary assembly poses a particular challenge is integral membrane proteins, which include hundreds of oligomeric ion channels, receptors, and transporters essential for cellular homeostasis. Many membrane protein subunits contain regions that, while necessary for function and oligomerization, would be thermodynamically unfavorable within the lipid bilayer. Very little is known about assembly factors that stabilize unassembled proteins in the ER membrane, or how these factors triage clients towards a biosynthetic or degradative fate. I propose to identify quality control factors that coordinate membrane protein assembly in mammals using two complementary strategies: in vitro biochemical analyses of the interactomes of orphan subunits and a genome-wide CRISPR/Cas9 knockout screen using a reporter cell line for membrane protein assembly. The identified candidates will be further analyzed using a combination of structural and functional strategies to examine the molecular mechanism of membrane protein complex assembly.

几乎所有的细胞过程，从DNA复制到细胞信号，都依赖于多亚单位蛋白质复合体。它们的组装必须受到高度调控，以确保生成化学计量比定义的功能性大分子。任何过多合成或仍未组装的孤儿亚基，必须由质量控制机构识别和降解，以防止非特异性结合和细胞毒性聚集。一类蛋白质的四级组装构成了一个特殊的挑战是完整的膜蛋白，它包括数百个寡聚离子通道，受体和转运体，对细胞的动态平衡至关重要。许多膜蛋白亚基包含一些区域，虽然这些区域是功能和寡聚所必需的，但在脂质双层中，这些区域在热力学上是不利的。人们对稳定内质网膜中未组装蛋白质的组装因子知之甚少，也不知道这些因素如何将客户分流到生物合成或降解的命运。我建议使用两种互补的策略来识别协调哺乳动物膜蛋白组装的质量控制因素：孤儿亚单位相互作用的体外生化分析和使用报告细胞系进行膜蛋白组装的全基因组CRISPR/Cas9基因敲除筛查。将使用结构和功能相结合的策略对已确定的候选进行进一步分析，以研究膜蛋白复合体组装的分子机制。

项目成果

WNK1 is an assembly factor for the human ER membrane protein complex.

• DOI: 10.1016/j.molcel.2021.04.013
• 发表时间: 2021-07-01
• 期刊: Molecular cell
• 影响因子: 16
• 作者: Pleiner T;Hazu M;Tomaleri GP;Januszyk K;Oania RS;Sweredoski MJ;Moradian A;Guna A;Voorhees RM
• 通讯作者: Voorhees RM