TOR signaling is involved in PTTH-stimulated ecdysteroidogenesis by prothoracic glands in the silkworm, Bombyx mori

► PTTH rapidly enhanced the phosphorylation of 4E-BP and S6K of prothoracic glands in Bombyx mori. ► Rapamycin treatment attenuated PTTH-stimulated phosphorylation of 4E-BP and S6K. ► PTTH-stimulated ecdysteroidogenesis was also inhibited by rapamycin treatment. ► PTTH/PI3K/TOR/4E-BP (S6K) signaling appears to be involved in PTTH-stimulated ecdysteroidogenesis.