FIG 7.

Glutamine, leucine, and arginine activate MTORC1 and inhibit ULK1 complex translocation to autophagosome assembly sites. HEK293A cells stably expressing LAMP1-mRFP were starved of amino acids for 2 h or starved for 110 min, followed by 10 min resupplementation with glutamine, leucine, and arginine (in the presence of 5% dialyzed FBS). The fixed cells were stained for endogenous MTOR (A), ULK1 (B), or ATG13 (C). The arrows in the enlarged insets indicate MTOR localized on lysosomal membranes in response to glutamine, leucine, and arginine (A) and localization of the ULK1 complex on autophagosome assembly sites juxtaposed to lysosomal membranes in response to amino acid starvation (B and C). Scale bars, 10 μm.