ANT-VDAC1 interaction is direct and depends on ANT isoform conformation in vitro

The voltage-dependent anion channel (VDAC) and the adenine nucleotide translocase (ANT) have central roles in mitochondrial functions such as nucleotides transport and cell death. The interaction between VDAC, an outer mitochondrial membrane protein and ANT, an inner membrane protein, was studied in isolated mitochondria and in vitro. Both proteins were isolated from various mitochondrial sources and reconstituted in vitro using a biomimetic system composed of recombinant human VDAC isoform 1 (rhVDAC1) immobilized on a surface plasmon resonance (SPR) sensor chip surface. Two enriched-preparations of HANT (ANT from heart, mainly ANT1) and LANT (ANT from liver, mainly ANT2) isoforms interacted differently with rhVDAC1. Moreover, the pharmacological ANT inhibitors atractyloside and bongkrekic acid modulated this interaction. Thus, ANT-VDAC interaction depends both on ANT isoform identity and on the conformation of ANT.

Highlight
► The interaction between ANT and VDAC was studied in isolated mitochondria and in vitro.
► ANT interactions were measured using rhVDAC1 immobilized on a SPR sensor chip.
► HANT (mainly ANT1) and LANT (mainly ANT2) isoforms interact differently with rhVDAC1.
► ANT binding to VDAC is dependent of ANT conformational state.