2′3′-cyclic GMP-AMP (2′3′-cGAMP), generated by cyclic GMP-AMP synthase (cGAS) under activation by cytosolic DNA, has a vital role in innate immune response via its receptor protein stimulator of interferon genes (STING) to fight viral infections and tumors. In order to have a complete understanding of biological functions of 2′3′-cGAMP, it is important to find out whether 2′3′-cGAMP has other unrevealed binding proteins present in mammalian cells and executes unknown functions. Here we report the 2′3′-cGAMP-based photoaffinity probes that capture and isolate 2′3′-cGAMP-binding proteins. These probes enable the identification of some potential 2′3′-cGAMP-binding proteins from HeLa cells. EF1A1, an essential protein regulating protein synthesis, is further validated to associate with 2′3′-cGAMP in vitro and in cells to impede protein synthesis. Thus, our studies provide a powerful approach to enable identification of the 2′3′-cGAMP interactome, discover unknown functions of 2′3′-cGAMP, and understand its physiological/pathological roles in tumor immunity and immune-related diseases.

2'3'-环状 GMP-AMP (2'3'-cGAMP) 在胞质 DNA 的激活下由环状 GMP-AMP 合酶 (cGAS) 产生，通过其干扰素基因的受体蛋白刺激物在先天免疫反应中发挥重要作用(STING) 对抗病毒感染和肿瘤。为了全面了解2'3'-cGAMP的生物学功能，重要的是要了解2'3'-cGAMP是否在哺乳动物细胞中存在其他未揭示的结合蛋白并执行未知功能。在这里，我们报告了捕获和分离 2'3'-cGAMP 结合蛋白的基于 2'3'-cGAMP 的光亲和探针。这些探针能够识别来自 HeLa 细胞的一些潜在的 2'3'-cGAMP 结合蛋白。EF1A1 是一种调节蛋白质合成的必需蛋白质，在体外被进一步证实与 2'3'-cGAMP 相关并在细胞中阻碍蛋白质合成。因此，我们的研究提供了一种强有力的方法来识别 2'3'-cGAMP 相互作用组，发现 2'3'-cGAMP 的未知功能，并了解其在肿瘤免疫和免疫相关疾病中的生理/病理作用。