[Functional and biochemical characterization of interleukin 2 receptor-associated molecules]

The interaction of interleukin 2 and the interleukin 2 receptor plays a crucial role in T cell proliferation. Unlike other growth factor receptors, the interleukin 2 receptor has a rudimentary intracytoplasmic portion that is too short to mediate any kinase activity. There are two classes of interleukin 2 receptor, with either high or low affinity. Only the high-affinity receptor mediates interleukin 2-driven transmembrane signal transduction. However, the mechanisms that control the affinity of the receptor and mediate transmembrane signal transduction are unknown. We report here that the rat interleukin 2 receptor has an associated molecule. The association of the rat interleukin 2 receptor with rat lymphocyte activation antigen, 5C6-F4 was demonstrated using the chemical cross-linking reagent, DTSSP. It is likely that the formation of a complex between the receptor and 5C6-F4 is important for the generation of the functional interleukin 2 receptor.