Figure 1. Schematic model for mode of cell death induced by stress in response to depleted intracellular ATP. Cellular stresses which deplete intracellular ATP induce a Ran gradient collapse and importin α accumulates in the nucleus. This leads to a block in classical nucleocytoplasmic protein transport via the importin α/β1 pathway. Nuclear importin α functions to elevate STK35 transcription and promotes non-apoptotic cell death in oxidative stress. The Ran gradient collapse may be induced by both ATP depletion and through modulated activity of Ran-related proteins, such as RCC1, in some stress conditions.⁹