Mitochondrial Binding of Hexokinase II Inhibits Bax-induced Cytochrome c Release and Apoptosis

Proapoptotic proteins such as Bax, undergo translocation to the mitochondria during apoptosis, where they mediate the release of intermembrane space proteins including cytochromec. Bax binds to the voltage-dependent anion channel (VDAC). VDAC is a β-barrel protein located in the outer mitochondrial membrane. In planar lipid bilayers, Bax and VDAC form a channel through which cytochrome c can pass. Hexokinase II (HXK II) also binds to VDAC. HXK II catalyzes the first step of glycolysis and is highly expressed in transformed cells, where over 70% of it is bound to the mitochondria. The present study demonstrates that HXK II interferes with the ability of Bax to bind to mitochondria and release cytochrome c.…

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  National Institutes of Health