I’ll Simply Die Without My Calcium: Ca²⁺ Signaling and Surviving Cellular Stress

A schematic representation of the calcium cell survival (CCS) pathway. By unknown means, cellular stressors such as unfolded proteins activate calcium entry (black) and pathways such as the UPR (gray). Calcium enters through at least two mechanisms, one of which is the Cch1-Mid1 channel. Initial calcium entry initiates a chain of events (red), including the activation of calmodulin, which leads to calcineurin activation. Calcineurin modulates calcium entry, thus sustaining Hac1-dependent transcription and other unknown activities, and ensuring cell survival.