[HTML][HTML] GAPDH and autophagy preserve survival after apoptotic cytochrome c release in the absence of caspase activation

A Colell, JE Ricci, S Tait, S Milasta, U Maurer… - Cell, 2007 - cell.com
A Colell, JE Ricci, S Tait, S Milasta, U Maurer, L Bouchier-Hayes, P Fitzgerald…
Cell, 2007cell.com
In cells undergoing apoptosis, mitochondrial outer-membrane permeabilization (MOMP) is
followed by caspase activation promoted by released cytochrome c. Although caspases
mediate the apoptotic phenotype, caspase inhibition is generally not sufficient for survival
following MOMP; instead cells undergo a" caspase-independent cell death"(CICD). Thus,
MOMP may represent a point of commitment to cell death. Here, we identify glyceraldehyde-
3-phosphate dehydrogenase (GAPDH) as a critical regulator of CICD. GAPDH-expressing …
Summary
In cells undergoing apoptosis, mitochondrial outer-membrane permeabilization (MOMP) is followed by caspase activation promoted by released cytochrome c. Although caspases mediate the apoptotic phenotype, caspase inhibition is generally not sufficient for survival following MOMP; instead cells undergo a "caspase-independent cell death" (CICD). Thus, MOMP may represent a point of commitment to cell death. Here, we identify glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a critical regulator of CICD. GAPDH-expressing cells preserved their clonogenic potential following MOMP, provided that caspase activation was blocked. GAPDH-mediated protection of cells from CICD involved an elevation in glycolysis and a nuclear function that correlated with and was replaced by an increase in Atg12 expression. Consistent with this, protection from CICD reflected an increase in and a dependence upon autophagy, associated with a transient decrease in mitochondrial mass. Therefore, GAPDH mediates an elevation in glycolysis and enhanced autophagy that cooperate to protect cells from CICD.
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