Figure 5
Proposed model of COX deficiency-induced apoptosis in response to oxidative stress. COX deficiency leads by an as yet unknown mechanism to enhanced expression of CerS6 (mainly associated with ER membranes) and accumulation of intracellular C16 : 0 ceramide (1). The increased intracellular C16 : 0 ceramide promotes the release of mitochondrial cytochrome c by involving Bax and Bak (2). The cytosolic cytochrome c induces the activation of initiator caspase-9 and downstream executioner caspases, finally resulting in apoptosis of the COX-deficient cell (3). Mt, mitochondria; PM, plasma membrane; RC, respiratory chain.
