[1] The amino acid response pathway is triggered by shortage of any essential amino acid, and results in an increase in activating transcription factor ATF4, which in turn affects many processes by sundry pathways to limit or increase the production of other proteins.
Diet plays an important role in the health of an organism, as evidence ranging from human epidemiological to model organism experimental data suggests that diet-dependent pathways impact a variety of adult stem cells.
[3] At low concentration of amino acid, GCN2 is activated due to the increase level of uncharged tRNA molecules.
Uncharged tRNA activates GCN2 due to the displacement of the protein kinase moiety from a bipartite tRNA-binding domain.
[9] PCAF is recruited specifically to the CHOP amino acid response element to enhance the ATF4 transcriptional activity.