Interleukin 9 (IL-9) is a T-cell-derived lymphokine that induces the proliferation of various lymphoid and hemopoietic cells. A cDNA clone encoding the murine IL-9 receptor was isolated by expression cloning in COS cells and screening with 125I-labeled IL-9. Transient expression of this cDNA produced high-affinity binding sites for IL-9. The predicted 52-kDa protein contains a putative signal peptide and a typical transmembrane domain. A cDNA for the human homologue was isolated by cross-hybridization. Transfection of this cDNA in a murine T-cell clone conferred responsiveness to human IL-9. Sequence analysis revealed that the IL-9 receptor belongs to the recently described hematopoietin receptor super-family and is expressed in membrane-bound and soluble forms.
Renauld, J.-C., Druez, C., Kermouni, A., Houssiau, F., Uyttenhove, C., Van Roost, E., & Van Snick, J. (1992). Expression cloning of the murine and human interleukin 9 receptor cDNAs. Proceedings of the National academy of sciences of the United States of America, 89(12), 5690-5694. https://doi.org/10.1073/pnas.89.12.5690 (Original work published 1992)