FIGURE 1: Differential signaling during oxidative stress via the cell wall integrity (CWI) pathway.

(A) The top left panel shows a dam with a spillway at the top. Low water levels are retained behind the dam and the only outflow is via the dam outlet at its base. The top right panel shows the result when water levels crest the dam and flow over the spillway. This leads to a larger downstream output.

(B) Signaling under either low (left side) or high (right side) oxidative stress conditions through the CWI pathway is shown. Note that these signaling events lead to the eventual degradation of cyclin C (Cnc1) as indicated by the dashed text. When Cnc1 is present, stress-responsive genes (SRG) are repressed and mitochondria exhibit a multilobe, fused morphology. Activation of the CWI pathway triggers Cnc1 degradation with accompanying mitochondrial fission, SRG activation and either programmed cell death (PCD) or repair of the stress-induced damage. See the text for further details.