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Caprin-1 binding to the critical stress granule protein G3BP1 is influenced by pH.

ABSTRACT: G3BP is the central node within stress-induced protein-RNA interaction networks known as stress granules (SGs). The SG-associated proteins Caprin-1 and USP10 bind mutually exclusively to the NTF2 domain of G3BP1, promoting and inhibiting SG formation, respectively. Herein, we present the crystal structure of G3BP1-NTF2 in complex with a Caprin-1-derived short linear motif (SLiM). Caprin-1 interacts with His-31 and His-62 within a third NTF2-binding site outside those covered by USP10, as confirmed using biochemical and biophysical-binding assays. Nano-differential scanning fluorimetry revealed reduced thermal stability of G3BP1-NTF2 at acidic pH. This destabilization was counterbalanced significantly better by bound USP10 than Caprin-1. The G3BP1/USP10 complex immunoprecipated from human U2OS cells was more resistant to acidic buffer washes than G3BP1/Caprin-1. Acidification of cellular condensates by approximately 0.5 units relative to the cytosol was detected by ratiometric fluorescence analysis of pHluorin2 fused to G3BP1. Cells expressing a Caprin-1/FGDF chimera with higher G3BP1-binding affinity had reduced Caprin-1 levels and slightly reduced condensate sizes. This unexpected finding may suggest that binding of the USP10-derived SLiM to NTF2 reduces the propensity of G3BP1 to enter condensates.

SUBMITTER: Schulte T

PROVIDER: S-EPMC10170197 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature

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Caprin-1 binding to the critical stress granule protein G3BP1 is influenced by pH.

Schulte Tim T Panas Marc D MD Han Xiao X Williams Lucy L Kedersha Nancy N Fleck Jonas Simon JS Tan Timothy J C TJC Dopico Xaquin Castro XC Olsson Anders A Morro Ainhoa Moliner AM Hanke Leo L Nilvebrant Johan J Giang Kim Anh KA Nygren Per-Åke PÅ Anderson Paul P Achour Adnane A McInerney Gerald M GM

Open biology 20230510 5

G3BP is the central node within stress-induced protein-RNA interaction networks known as stress granules (SGs). The SG-associated proteins Caprin-1 and USP10 bind mutually exclusively to the NTF2 domain of G3BP1, promoting and inhibiting SG formation, respectively. Herein, we present the crystal structure of G3BP1-NTF2 in complex with a Caprin-1-derived short linear motif (SLiM). Caprin-1 interacts with His-31 and His-62 within a third NTF2-binding site outside those covered by USP10, as confirm ...[more]

PMID: 37161291

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Dataset Information

Caprin-1 binding to the critical stress granule protein G3BP1 is influenced by pH.

Publications

Caprin-1 binding to the critical stress granule protein G3BP1 is influenced by pH.

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