IL-7 Induces an Epitope Masking of γc Protein in IL-7 Receptor Signaling Complex

Figure 5

Model of IL-7Rα/γc receptor core conformational states in the absence or presence of IL-7. This model builds on the concept that binding affinity between IL-7Rα and γc is present on the cell surface as inactive heterodimers. In the absence of IL-7, ligand independent association of IL-7Rα and γc would keep JAK1 and JAK3 separated by a large distance to prevent activation. Once IL-7 binds to IL-7Rα/γc receptor core, the receptors undergo a conformational change, locating the two intracellular domains and activating the signal transduction. At a later stage of IL-7 signaling, IL-7Rα is internalized, degraded, and transcriptionally terminated, in which the epitopes masked by IL-7/IL-7Rα are reexposed in free γc.