Transmembrane signaling of interleukin 2 receptor. Conformation and function of human interleukin 2 receptor (p55)/insulin receptor chimeric molecules

Chimeric genes were constructed which gave rise to the expression of novel receptor molecules consisting of the extracellular domain of the human interleukin 2 receptor (IL-2-R; p55 or Tac antigen) joined to the transmembrane domain and either full-length or truncated cytoplasmic domain of the human insulin receptor (Ins-R). Expression studies using mouse T cell line EL-4 revealed that the chimeric receptors are able to manifest properties indistinguishable from the authentic IL-2-R. On the other hand, stimulation of the tyrosine kinase activity by IL-2 was not observed in the chimeric receptor with the entire cytoplasmic domain of the Ins-R. These findings thus shed light on the structural conformation and functioning of the IL-2-R complex.