FIGURE 10.

A model: E93 transcriptionally modulates 20E signaling to promote Bombyx larval-pupal metamorphosis. Induced by 20E and suppressed by JH, E93 is abundantly expressed during the larval-pupal metamorphosis. At this stage, E93 acts through GAGA-containing motifs to induce expression of a subset of 20E-response genes, positively affects 20E signaling, and promotes larval tissue remodeling and adult tissue formation. The expression level of E93 is induced by 20E-EcR-USP, but the transcriptional activity of E93 is attenuated by its physical association with USP. Notably, the E93 action to modulate 20E signaling is both dependent and independent on 20E-EcR-USP. Text and arrow sizes convey magnitude of signal transduction.