Eukaryotic translation initiation factor 2-alpha kinase 4 (GCN2) (GCN2)

Eukaryotic translation initiation factor 2-alpha kinase 4 (EIF2AK4), commonly known as GCN2, is a serine/threonine kinase that serves as a critical sensor of amino acid availability. Upon sensing uncharged tRNAs during nutrient deprivation, GCN2 phosphorylates the alpha subunit of eIF2, triggering the Integrated Stress Response (ISR) to reprogram cellular translation and metabolism. In enterocytes, the GCN2 pathway is essential for maintaining intestinal homeostasis; it promotes autophagy and suppresses reactive oxygen species (ROS)-mediated inflammasome activation, thereby protecting the gut from inflammatory damage and colitis. While GCN2 inhibition is being explored as a strategy to sensitize cancer cells to metabolic stress, its role in the intestinal epithelium suggests that such therapies must be carefully managed to avoid exacerbating gastrointestinal inflammation. Conversely, pharmacological activation of the GCN2 pathway in the gut represents a potential therapeutic avenue for treating inflammatory bowel diseases.

Other names

EIF2AK4General control nonderepressible 2eIF-2-alpha kinase GCN2GCN2-like protein

GCN2 inhibitors block the phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF2-alpha), preventing the activation of the Integrated Stress Response (ISR) and downstream transcription factors like ATF4, which sensitizes cells to nutrient stress. Conversely, GCN2 activators or inducers (such as Halofuginone or amino acid restriction) trigger the ISR to promote cytoprotective autophagy and suppress inflammasome activation in the intestinal epithelium.