Figure 5.
Mammalian cell growth requires growth factors and nutrients. Glucose is shown to signal to MondoA, which down-modulates glucose metabolism. Glutamine contributes to mTORC1 activation through import of leucine and production of GTP via the TCA cycle. GTP is required for mTORC1 activation by its association with lysosomal membranes. mTORC1 activation of S6K1 stimulates ribosome biogenesis (Ribi) genes. Growth factor signaling through receptor tyrosine kinase (RTK) activates PI3K and mTORC2, resulting in AKT activation that stimulates glucose metabolism. Signal transduction via MEK to MYC initiates a transcriptional program that stimulates Ribi genes, coupled with increased glucose and glutamine metabolic gene expression.