Targeting G3BP1 Condensate Topology Promotes Stress Granule Assembly via m6A‐IGF2BP1 for Ischemic Stroke Rescue

Our research reveals that small‐molecule icariin (ICA) directly binds Ras‐GTPase‐activating protein SH3 domain‐binding protein 1 (G3BP1), inducing conformational change and oligomerization. This interaction confers neuroprotection by recruiting insulin‐like growth factor 2 mRNA‐binding protein 1 (IGF2BP1) and modulating N6‐methyladenosine (m6A) modifications. Moreover, a distinct neuronal subset exhibits ICA sensitivity correlated with G3BP1 expression, suggesting therapeutic potential for stroke. 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 N6‐methyladenosine (m6A) reader insulin‐like growth factor 2 mRNA‐binding protein 1 (IGF2BP1) through topology‐selective scaffolding, establishing epitranscriptomic hubs that resolve proteotoxic stress via m6A‐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–m6A 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. Our research reveals that small-molecule icariin (ICA) directly binds Ras-GTPase-activating protein SH3 domain-binding protein 1 (G3BP1), inducing conformational change and oligomerization. This interaction confers neuroprotection by recruiting insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) and modulating N 6 -methyladenosine (m 6 A) modifications. Moreover, a distinct neuronal subset exhibits ICA sensitivity correlated with G3BP1 expression, suggesting therapeutic potential for stroke. 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. Advanced Science, EarlyView.