GCN2 (EIF2AK4)

Class

Small molecule kinase inhibitor

Pathway

Integrated stress response / proteostasis regulation in leukemic cells

GCN2 (also called EIF2AK4) is a kinase that acts as an internal stress sensor. It is part of the integrated stress response (ISR), a signaling network cells use to adapt to conditions such as amino acid shortage, oxidative stress, or a buildup of misfolded proteins. Once activated, GCN2 adds a phosphate group to a protein called eIF2α, which slows general protein production while selectively increasing synthesis of stress-response proteins such as ATF4. This helps cells manage proteostasis, the balance between making, folding, and clearing proteins, by easing the folding workload and turning on genes for amino acid metabolism and antioxidant defense.

Some cancers, including leukemias, grow in nutrient-poor, metabolically stressed environments and depend on GCN2-driven ISR signaling to tolerate these conditions. A small molecule that inhibits GCN2 could impair this adaptive response, making malignant cells less able to withstand nutrient and proteotoxic stress, potentially amplifying the effect of other treatments that increase such stress. This mechanism is of broad interest across cancer types where proteostasis pathways support tumor survival, rather than being tied to one specific disease.