Activation of the Hog1p kinase in Isc1p-deficient yeast cells is associated with mitochondrial dysfunction, oxidative stress sensitivity and premature aging

► Hog1p is activated by ceramide. ► Hyperactivation of Hog1p is associated with premature aging of isc1Δ cells. ► HOG1 deletion restores mitochondrial function of isc1Δ cells. ► Downstream of Hog1p, Isc1p deficiency activates the cell wall integrity (CWI) pathway. ► The phenotypes of isc1Δ cells are not associated with cell wall defects.