Amino acid deprivation regulates the stress-inducible gene p8 via the GCN2/ATF4 pathway

In mammals, the GCN2/ATF4 pathway has been described as the main pathway involved in the regulation of gene expression upon amino acid limitation. This regulation is notably conferred by the presence of a cis-element called Amino Acid Response Element (AARE) in the promoter of specific genes. In vivo, the notion of amino acid limitation is not limited to nutritional context, indeed several pathological situations are associated with alteration of endogenous amino acid availability. This is notably true in the context of tumour in which the alteration of the microenvironment can lead to a perturbation in nutrient availability. P8 is a small weakly folded multifunctional protein that is overexpressed in several kinds of cancers and whose expression is induced by different stresses. In this study we have demonstrated that amino acid starvation was also able to induce p8 expression. Moreover, we brought the evidence, in vitro and in vivo, that the GCN2/ATF4 pathway is involved in this regulation through the presence of an AARE in p8 promoter.