The voltage-dependent anion channel-1 modulates apoptotic cell death.
The role of the voltage-dependent anion channel (VDAC) in cell death was investigated using the expression of native and mutated murine VDAC1 in U-937 cells and VDAC inhibitors. Glutamate 72 in VDAC1, shown previously to bind dicyclohexylcarbodiimide (DCCD), which inhibits hexokinase isoform I (HK-I) binding to mitochondria, was mutated to glutamine. Binding of HK-I to mitochondria expressing E72Q-mVDAC1, as compared to native VDAC1, was decreased by approximately 70% and rendered insensitive to DCCD. HK-I and ruthenium red (RuR) reduced the VDAC1 conductance but not that of E72Q-mVDAC1. Overexpression of native or E72Q-mVDAC1 in U-937 cells induced apoptotic cell death (80%). RuR or overexpression of HK-I prevented this apoptosis in cells expressing native but not E72Q-mVDAC1. Thus, a single amino-acid mutation in VDAC prevented HK-I- or RuR-mediated protection against apoptosis, suggesting the direct VDAC regulation of the mitochondria-mediated apoptotic pathway and that the protective effects of RuR and HK-I rely on their binding to VDAC.
Zaid
H
H
Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Abu-Hamad
S
S
Israelson
A
A
Nathan
I
I
Shoshan-Barmatz
V
V
D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001665:Binding Sites; D015870:Gene Expression; D006593:Hexokinase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D018272:Porins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics; D012430:Ruthenium Red / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D020298:U937 Cells; D050995:Voltage-Dependent Anion Channel 1; D050994:Voltage-Dependent Anion Channels
D018272:Porins; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; C494762:VDAC1 protein, human; C494763:Vdac1 protein, mouse; C494764:Vdac1 protein, rat; D050994:Voltage-Dependent Anion Channels; D012430:Ruthenium Red; D050995:Voltage-Dependent Anion Channel 1; D006593:Hexokinase