Figure 4. Putative effects of sol IGF-1R on GH signaling.
A) GH enhances association of GHR/JAK2 with IGF-1R, augmenting GH signaling, as in Figure 3A. Strong GH-induced signaling is indicated by “SIGNAL”. B) GH induces GHR/sol IGF-1R association and dampened signaling ensues. Sol IGF-1R contains the L1-CR-L2 region (CR-L2 region in black). Sol IGF-1R allows GH-induced GHR and JAK2 conformational changes and signaling, but competes with IGF-1 R for GHR association. GH signaling is similar in strength as with IGF-1R silencing seen in Figure 3B. See the text for discussion.