Targeting G3BP1 Condensate Topology Promotes Stress Granule Assembly via m 6 A‐IGF2BP1 for Ischemic Stroke Rescue

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Abstract Ras‐GTPase‐activating protein SH3 domain‐binding protein 1 (G3BP1) mediates stress granules (SGs) via phase separation. However, there is limited understanding of the allosteric mechanism and the identification of regulatory molecules. Here, we identify icariin (ICA), a small‐molecule inducer that promotes G3BP1‐driven biomolecular condensate formation, which effectively restructures SGs architecture. Moreover, we demonstrate that ICA interacts with the N‐terminal nuclear transport factor 2‐like (NTF2L) domain of G3BP1, inducing a conformational switch from “closed‐to‐open” that facilitates G3BP1 oligomerization and phase separation. Crucially, G3BP1 condensates recruit N 6 ‐methyladenosine (m 6 A) reader insulin‐like growth factor 2 mRNA‐binding protein 1 (IGF2BP1) through topology‐selective scaffolding, establishing epitranscriptomic hubs that resolve proteotoxic stress via m 6 A‐dependent AMP‐activated protein kinase (AMPK)‐mitogen‐activated protein kinase (MAPK)‐glutathione peroxidase 4 (GPX4) signaling pathways. Strikingly, this chemical intervention shows translational potential, as ICA reduces cerebral infarct volume in ischemia models via G3BP1‐dependent SGs remodeling. Additionally, single‐nucleus transcriptomics identify Fezf2 , Pou3f1 , and Kcnn2 neuronal subpopulations as mechanistically aligned responders. Furthermore, ischemic stroke patients reveal G3BP1–IGF2BP1–m 6 A axis within peripheral blood mononuclear cells. Taken together, this study redefines SGs as dynamically druggable epitranscriptomic processors for precision neuroprotection. In particular, a framework for leveraging biomolecular condensate topology in the development of next‐generation neurological therapeutics is offered.

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