Munro S, Maniatis T
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, MA 02138.
Proc Natl Acad Sci U S A. 1989 Dec;86(23):9248-52. doi: 10.1073/pnas.86.23.9248.
A cDNA encoding a receptor for murine interferon gamma (IFN-gamma) was isolated from an expression library made from murine thymocytes. The clone was identified by transfecting the library into monkey COS cells and probing the transfected monolayer with radiolabeled murine IFN-gamma. Cells expressing the receptor were identified by autoradiography and plasmids encoding the receptor were directly rescued from those cells producing a positive signal. A partial cDNA so obtained was used to isolate a full-length cDNA from mouse L929 cells by conventional means. When this cDNA was expressed in COS cells it produced a specific binding site for murine IFN-gamma with an affinity constant similar to that of the receptor found on L929 cells. The predicted amino acid sequence of the murine IFN-gamma receptor shows homology to that previously reported for the human IFN-gamma receptor. However, although the two proteins are clearly related, they show less than 60% identity in both the putative extracellular domain and the intracellular domain.
从由小鼠胸腺细胞构建的表达文库中分离出一个编码小鼠γ干扰素（IFN-γ）受体的cDNA。通过将该文库转染到猴COS细胞中，并用放射性标记的小鼠IFN-γ探测转染的单层细胞来鉴定该克隆。通过放射自显影鉴定表达受体的细胞，并直接从产生阳性信号的细胞中拯救出编码该受体的质粒。用如此获得的部分cDNA，通过常规方法从小鼠L929细胞中分离出全长cDNA。当该cDNA在COS细胞中表达时，它产生了一个与小鼠IFN-γ的特异性结合位点，其亲和常数与在L929细胞上发现的受体相似。小鼠IFN-γ受体的预测氨基酸序列与先前报道的人IFN-γ受体的氨基酸序列具有同源性。然而，尽管这两种蛋白质明显相关，但它们在假定的细胞外结构域和细胞内结构域中的同一性均低于60%。
