The protein kinase complex mTORC1 regulates growth and metabolism, and its activity is controlled in response to the abundance of cellular amino acids. Jewell et al. report that control of mTORC1 in response to glutamine does not require the Rag guanosine triphosphatase (GTPase) implicated in the sensing of other amino acids such as leucine (see the Perspective by Abraham). For sensing of glutamine, another GTPase, Arf1, was required. Distinct mechanisms thus appear to couple various amino acids to signaling by the mTORC1 complex.
J. L. Jewell, Y. C. Kim, R. C. Russell, F.-X. Yu, H. W. Park, S. W. Plouffe, V. S. Tagliabracci, K.-L. Guan, Differential regulation of mTORC1 by leucine and glutamine. Science 347, 194–198 (2015). [Abstract] [Full Text]
R. T. Abraham, Making sense of amino acid sensing. Science 347, 128–129 (2015). [Summary] [Full Text]
