Croze E, Russell-Harde D, Wagner T C, Pu H, Pfeffer L M, Perez H D
Department of Protein Biochemistry and Biophysics, Berlex Biosciences, Richmond, California 94804, USA.
J Biol Chem. 1996 Dec 27;271(52):33165-8. doi: 10.1074/jbc.271.52.33165.
We used specific antibodies recognizing the receptor 1 (IFNAR1) and the recently cloned receptor 2.2 (IFNAR2.2) chains of the human type I interferon receptor complex to demonstrate that the interferon beta (IFN-beta)-specific receptor-associated phosphoprotein is IFNAR2.2 and not an unknown or additional receptor component. Immunoprecipitation experiments demonstrated that IFNAR2.2 is present in Daudi cells as a cell surface protein of approximately 90-100 kDa, which is tyrosine-phosphorylated and associated with IFNAR1, upon stimulation of cells with IFN-beta. IFNAR2.2 was not detected associated with IFNAR1 in cells stimulated with IFN-alpha, suggesting differences in receptor interaction between the two type I interferons. Both IFNAR1 and IFNAR2.2 undergo tyrosine phosphorylation upon induction by either IFN-alpha or IFN-beta. Therefore, it is unclear as to why IFNAR2.2 is not detectable in IFNAR1 immunoprecipitates in IFN-beta-treated cells. These data suggest that, although IFN-alpha and IFN-beta may utilize similar receptor chains, they interact with IFNAR1 and IFNAR2.2 in different ways.
我们使用了特异性抗体来识别人类I型干扰素受体复合物的受体1（IFNAR1）和最近克隆的受体2.2（IFNAR2.2）链，以证明干扰素β（IFN-β）特异性受体相关磷蛋白是IFNAR2.2，而非未知或额外的受体成分。免疫沉淀实验表明，在Daudi细胞中，IFNAR2.2作为一种约90-100 kDa的细胞表面蛋白存在，在用IFN-β刺激细胞后，该蛋白会发生酪氨酸磷酸化并与IFNAR1相关联。在用IFN-α刺激的细胞中未检测到IFNAR2.2与IFNAR1相关联，这表明两种I型干扰素在受体相互作用方面存在差异。IFNAR1和IFNAR2.2在受到IFN-α或IFN-β诱导后都会发生酪氨酸磷酸化。因此，尚不清楚为何在IFN-β处理的细胞中，IFNAR1免疫沉淀物中检测不到IFNAR2.2。这些数据表明，尽管IFN-α和IFN-β可能利用相似的受体链，但它们与IFNAR1和IFNAR2.2的相互作用方式不同。
