Mallik Saurav, Venezian Johannes, Lobov Arseniy, Heidenreich Meta, Garcia-Seisdedos Hector, Yeates Todd O, Shiber Ayala, Levy Emmanuel D
Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7600001, Israel.
Faculty of Biology, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
Cell. 2025 Feb 6;188(3):764-777.e22. doi: 10.1016/j.cell.2024.11.013. Epub 2024 Dec 20.
Protein assembly into functional complexes is critical to life's processes. While complex assembly is classically described as occurring between fully synthesized proteins, recent work showed that co-translational assembly is prevalent in human cells. However, the biological basis for the existence of this process and the identity of protein pairs that assemble co-translationally remain unknown. We show that co-translational assembly is governed by structural characteristics of complexes and involves mutually stabilized subunits. Accordingly, co-translationally assembling subunits are unstable in isolation and exhibit synchronized proteostasis with their partner. By leveraging structural signatures and AlphaFold2-based predictions, we accurately predicted co-translational assembly, including pair identities, at proteome scale and across species. We validated our predictions by ribosome profiling, stoichiometry perturbations, and single-molecule RNA-fluorescence in situ hybridization (smFISH) experiments that revealed co-localized mRNAs. This work establishes a fundamental connection between protein structure and the translation process, highlighting the overarching impact of three-dimensional structure on gene expression, mRNA localization, and proteostasis.
蛋白质组装成功能复合物对生命过程至关重要。虽然传统上认为复合物组装发生在完全合成的蛋白质之间，但最近的研究表明，共翻译组装在人类细胞中很普遍。然而，这一过程存在的生物学基础以及共翻译组装的蛋白质对的身份仍然未知。我们发现，共翻译组装受复合物结构特征的支配，并且涉及相互稳定的亚基。因此，共翻译组装的亚基单独存在时不稳定，并与其伴侣表现出同步的蛋白质稳态。通过利用结构特征和基于AlphaFold2的预测，我们在蛋白质组规模和跨物种水平上准确预测了共翻译组装，包括配对身份。我们通过核糖体分析、化学计量扰动和揭示共定位mRNA的单分子RNA荧光原位杂交（smFISH）实验验证了我们的预测。这项工作建立了蛋白质结构与翻译过程之间的基本联系，突出了三维结构对基因表达、mRNA定位和蛋白质稳态的总体影响。
