Production and characterization of the extracytoplasmic portion of the human interleukin-2 receptor.
We made a mutant cDNA clone of the human interleukin-2 (IL-2) receptor by introducing a termination codon at the eighth amino acid residue upstream from the putative transmembrane region. Ltk- cells were transfected by this mutant cDNA and cell-lines secreting the extracytoplasmic portion of the IL-2 receptor were established. The artificial secretory molecule of the IL-2 receptor named "bottom-less" receptor was able to react with anti-Tac antibody and to bind IL-2. We purified the bottom-less receptor to homogeneity by affinity chromatography using an IL-2-Sepharose column. The affinity (Kd value) of the 125I-labeled bottom-less receptor to IL-2 coupled to Sepharose beads was estimated to be 4.5 microM. All these results confirm the putative membrane topology of the IL-2 receptor based on the primary structure, and suggest that the bottom-less receptor may maintain the basic structure and function of the extracytoplasmic portion of the IL-2 receptor.
D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D009154:Mutation; D011971:Receptors, Immunologic / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D015375:Receptors, Interleukin-2
D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D004247:DNA