Fig. 1

Main protein of mTORC1 signal pathway (mTORC1 is comprised by mTOR, Deptor, mLST8, Raptor, PRAS40. mTORC1 regulates cell function almost through phosphorylating the downstream protein of mTORC1, including PR-S6K and EIF4EBP. After getting phosphorylated by mTORC1, PR-S6K activates EIF-4B, which positively regulates EIF-4F. RP-S6K also phosphorylates and promotes the degradation of PDCD4, which is the inhibitor of EIF-4B. EIF4EBP is a repressor of EIF-4E, once phosphorylated by mTORC1, it dissociate with EIF-4E, and then promotes the assembly of EIF-4F complex. The EIF-4F complex is composed by EIF-4E, EIF-4G, and EIF-4A. The specificity repressor of mTORC1-rapamycin can combine with mTOR, and induce conformational change in mTORC1. RP-S6K, ribosomal protein S6K kinase; EIF4EBP, eukaryotic initiation factor 4E-binding protein; EIF-4G, translation initiation factor 4G; EIF-4E, translation initiation factor 4E; EIF-4A, translation initiation factor 4A)