Figure 1. FIGURE 1: Cytokine-induced receptor heterodimerization signaling mechanisms.

During the initiation step, IL-7 interacts with the extracellular domain 1 (D1) of IL-7Rα, generating the site-1 interface. This leads to the intermediate step where a 1:1 complex can associate with the shared common gamma-chain (γ_c) receptor. The binding of γ_c receptor involves an interface between IL-7 and γ_c called site-2a and an interface between D2 regions of the IL-7Rα and γ_c receptor called site-2b. The stabilized heterodimer complex activates the JAK/STAT and possible other signaling pathways.