Raptor Rheb:GTP Activated mTORC1 Formation of active mTORC1 complex Pubmed15755954 Reactome Database ID Release 43165680 Reactome, http://www.reactome.org ReactomeREACT_6851 mTOR forms a functional protein complex with at least two proteins: Raptor (Regulated Associated Protein of mTOR) and mLst8. This complex is called mammalian TOR complex 1 (mTORC1). Raptor serves as a scaffolding protein to bridge the interaction between mTOR and its substrates. mLst8 enhances the association of mTOR with Raptor. [Rheb:GTP] binds and activates mTORC1. Besides binding directly to mTOR, Rheb can also bind to Raptor and mLst8 (PMIDs 15854902, 15755954 and 12150926).