Glutaminase contributes to MYC-induced cell-autonomous autophagy and to Ras ^V12 -dependent non-autonomous autophagy in the Drosophila wing disc epithelium

MYC-driven metabolic reprogramming supports rapid cell growth but also creates metabolic demands that require adaptive mechanisms to maintain cellular homeostasis. Here, combining clonal analysis in Drosophila wing imaginal discs with studies in Schneider S2 cells, we identify glutamine metabolism as a component of Myc-induced autophagy. Myc increased the expression of genes involved in glutamine utilization, including glutaminase (GLS), and enhanced ammonia production, a metabolic by-product of glutaminolysis. Genetic depletion of GLS in clones suppressed the accumulation of Myc-induced Atg8a-positive structures and reduced autophagic flux, demonstrating that glutaminase contributes to the autophagic response elicited by Myc. Exogenous NH₄Cl was sufficient to induce Atg8a-positive structures and partially restored their accumulation following GLS depletion, supporting ammonia as a downstream contributor to this response. Mechanistically, Myc-induced autophagy in clones required the core autophagy factor Atg5 but was not suppressed by activation of Rheb/TOR signaling or Atg1 depletion, indicating reduced dependence on canonical TOR-Atg1 regulation. We further found that Myc activity is required for Ras ^V12 -driven epithelial overgrowth and that Ras ^V12 cells induce a pronounced non-cell-autonomous accumulation of Atg8a-positive structures in wild-type cells surrounding Ras ^V12 clones. Depletion of either Myc or Gls in Ras ^V12 cells strongly reduced this neighboring autophagic response. Together, our findings identify Gls-dependent glutamine metabolism as a previously unrecognized component of Myc-induced autophagy and extend this relationship to Ras-transformed epithelia, linking the metabolic state of transformed cells to autophagy in the surrounding tissue.