Figure 5: GCN2 is necessary for the regulation of mTORC1 by arginine.
From: GCN2 contributes to mTORC1 inhibition by leucine deprivation through an ATF4 independent mechanism
(A) WT or GCN2−/− MEFs were cultured in presence or in absence of arginine (Arg) with all the other AAs for 30, 60 or 120 min. The ratio of phosphorylated S6K1 (Thr389) to total S6K1 was determined by densitometry analysis, differences between control cells (dark bars) and arginine starved cells (light bars) at each time point were assessed by 1-way ANOVA. Bars with (*) are significantly different from each other (P < 0.05). (B) WT MEFs and GCN2−/− MEFs were cultured in the presence or absence of AA for 75 min; or in absence of AA for 60 min prior to addition for 15 min of a medium containing all AA (−AA → + AA) or a medium containing all AA except arginine (−AA → -Arg). Immunoblot analyses were performed to assess the amounts of the indicated proteins and their levels of phosphorylation.
