Bischoff J R, Samuel C E
J Biol Chem. 1985 Jul 15;260(14):8237-9.
Protein P1, the interferon-induced protein phosphorylated in the presence of dsRNA in human amnion U-cells, was covalently labeled with [alpha-32P]ATP following ultraviolet irradiation. The photoaffinity labeling of protein P1 was dependent upon double-stranded RNA. Antibody prepared against phosphorylated protein P1 immunoprecipitated the double-stranded RNA-dependent photoaffinity-labeled product. The extent of photoaffinity labeling was significantly decreased by the addition of unlabeled ATP, GTP, or AMP; adenosine had little effect on the photoaffinity labeling of protein P1. These results suggest that protein P1 possesses a site capable of binding an adenine nucleotide in a double-stranded RNA-dependent manner.
蛋白质P1是在人羊膜U细胞中存在双链RNA时被磷酸化的干扰素诱导蛋白，在紫外线照射后用[α-32P]ATP进行了共价标记。蛋白质P1的光亲和标记依赖于双链RNA。针对磷酸化蛋白质P1制备的抗体免疫沉淀了双链RNA依赖性光亲和标记产物。加入未标记的ATP、GTP或AMP会显著降低光亲和标记的程度；腺苷对蛋白质P1的光亲和标记几乎没有影响。这些结果表明蛋白质P1具有一个能够以双链RNA依赖性方式结合腺嘌呤核苷酸的位点。
