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Published on: October 23, 2018
Glutamine and asparagine activate mTORC1 independently of Rag GTPases
Delong Meng1, Qianmei Yang1, Huanyu Wang1
1Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390; Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390.
Abstract:
Nutrient sensing by cells is crucial, and when this sensing mechanism is disturbed, human disease can occur. mTOR complex 1 (mTORC1) senses amino acids to control cell growth, metabolism, and autophagy. Leucine, arginine, and methionine signal to mTORC1 through the well-characterized Rag GTPase signaling pathway. In contrast, glutamine activates mTORC1 through a Rag GTPase-independent mechanism that requires ADP-ribosylation factor 1 (Arf1). Here, using several biochemical and genetic approaches, we show that eight amino acids filter through the Rag GTPase pathway. Like glutamine, asparagine signals to mTORC1 through Arf1 in the absence of the Rag GTPases. Both the Rag-dependent and Rag-independent pathways required the lysosome and lysosomal function for mTORC1 activation. Our results show that mTORC1 is differentially regulated by amino acids through two distinct pathways.
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