Hu Jiaojiao, Dong Hui, Li Yichen, Gu Jinge, Yang Liang, Si Chenfang, Zhang Yaoyang, Li Tingting, Li Dan, Liu Cong
Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 201210 China
State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 China.
Chem Sci. 2024 Jun 10;15(27):10508-10518. doi: 10.1039/d4sc00267a. eCollection 2024 Jul 10.
Hsp90α, a pivotal canonical chaperone, is renowned for its broad interaction with numerous protein clients to maintain protein homeostasis, chromatin remodeling, and cell growth. Recent studies indicate its role in modifying various components of membraneless organelles (MLOs) such as stress granules and processing bodies, suggesting its participation in the regulation of protein condensates. In this study, we found that Hsp90α possesses an inherent ability to form dynamic condensates . Utilizing LC-MS/MS, we further pinpointed proteins in cell lysates that preferentially integrate into Hsp90α condensates. Significantly, we observed a prevalence of RG motif repeats in client proteins of Hsp90α condensates, many of which are linked to various MLOs. Moreover, each of the three domains of Hsp90α was found to undergo phase separation, with numerous solvent-exposed negatively charged residues on these domains being crucial for driving Hsp90α condensation through multivalent weak electrostatic interactions. Additionally, various clients like TDP-43 and hnRNPA1, along with poly-GR and PR dipeptide repeats, exhibit varied impacts on the dynamic behavior of Hsp90α condensates. Our study spotlights various client proteins associated with Hsp90α condensates, illustrating its intricate adaptive nature in interacting with diverse clients and its functional adaptability across multiple MLOs.
热休克蛋白90α（Hsp90α）是一种关键的典型分子伴侣，以其与众多蛋白质底物的广泛相互作用而闻名，可维持蛋白质稳态、染色质重塑和细胞生长。最近的研究表明，它在修饰无膜细胞器（MLO）的各种成分（如应激颗粒和加工小体）中发挥作用，这表明它参与了蛋白质凝聚物的调控。在本研究中，我们发现Hsp90α具有形成动态凝聚物的内在能力。利用液相色谱-串联质谱（LC-MS/MS），我们进一步确定了细胞裂解物中优先整合到Hsp90α凝聚物中的蛋白质。值得注意的是，我们观察到Hsp90α凝聚物的底物蛋白中普遍存在RG基序重复，其中许多与各种MLO相关。此外，发现Hsp90α的三个结构域中的每一个都能发生相分离，这些结构域上大量暴露于溶剂中的带负电荷残基对于通过多价弱静电相互作用驱动Hsp90α凝聚至关重要。此外，诸如TDP-43和hnRNPA1等各种底物，以及聚GR和PR二肽重复序列，对Hsp90α凝聚物的动态行为表现出不同的影响。我们的研究突出了与Hsp90α凝聚物相关的各种底物蛋白，阐明了其在与不同底物相互作用中的复杂适应性本质及其在多个MLO中的功能适应性。
