Amino acid deprivation induces AKT activation by inducing GCN2/ATF4/REDD1 axis

• Published in: Cell death & disease Vol. 12; no. 12; p. 1127
• Main Authors: Jin, Hyeon-Ok, Hong, Sung-Eun, Kim, Ji-Young, Jang, Se-Kyeong, Park, In-Chul
• Format: Journal Article
• Language: English
• Published: England Springer Nature B.V 03.12.2021; Nature Publishing Group UK; Nature Publishing Group
• Subjects: Activating Transcription Factor 4 - genetics; Activating Transcription Factor 4 - metabolism; AKT protein; Amino acids; Amino Acids - metabolism; Cancer; Carcinoma, Non-Small-Cell Lung; Cell activation; Cell survival; CRISPR; Glutamine; Humans; Lung Neoplasms - genetics; Lysine; Mechanistic Target of Rapamycin Complex 1 - metabolism; Methionine; Non-small cell lung carcinoma; Proto-Oncogene Proteins c-akt - metabolism; Radiation therapy; Rapamycin; Small cell lung carcinoma; TOR protein
• ISSN: 2041-4889; 2041-4889
• DOI: 10.1038/s41419-021-04417-w

Amino acid availability is sensed by various signaling molecules, including general control nonderepressible 2 (GCN2) and mechanistic target of rapamycin complex 1 (mTORC1). However, it is unclear how these sensors are associated with cancer cell survival under low amino acid availability. In the present study, we investigated AKT activation in non-small cell lung cancer (NSCLC) cells deprived of each one of 20 amino acids. Among the 20 amino acids, deprivation of glutamine, arginine, methionine, and lysine induced AKT activation. AKT activation was induced by GCN2/ATF4/REDD1 axis-mediated mTORC2 activation under amino acid deprivation. In CRISPR-Cas9-mediated REDD1-knockout cells, AKT activation was not induced by amino acid deprivation, indicating that REDD1 plays a major role in AKT activation under amino acid deprivation. Knockout of REDD1 sensitized cells cultured under glutamine deprivation conditions to radiotherapy. Taken together, GCN2/ATF4/REDD1 axis induced by amino acid deprivation promotes cell survival signal, which might be a potential target for cancer therapy.