High-content imaging, immunoblot and immunofluorescence data related to: Caprin-1 binding to the critical stress granule protein G3BP1 is influenced by pH

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 fluorescen...G3BP是被称为应激颗粒（stress granules, SGs）的应激诱导蛋白-RNA互作网络中的核心节点。与应激颗粒相关的Caprin-1和USP10可互斥结合G3BP1的NTF2结构域，分别促进和抑制应激颗粒的形成。本研究解析了G3BP1-NTF2与Caprin-1衍生的短线性基序（short linear motif, SLiM）结合的晶体结构。经生化与生物物理结合实验验证，Caprin-1与USP10结合位点之外的第三个NTF2结合位点内的His-31和His-62发生相互作用。纳米差示扫描荧光法（nano-differential scanning fluorimetry）结果显示，G3BP1-NTF2在酸性pH条件下热稳定性降低。相较于结合Caprin-1，结合USP10可更显著地抵消该热稳定性下降现象。从人U2OS细胞中免疫沉淀获得的G3BP1/USP10复合物，相较于G3BP1/Caprin-1复合物，对酸性缓冲液洗涤的耐受性更强。通过比率荧光检测发现，细胞凝聚体的酸化程度较细胞质高约0.5个单位