VDAC oligomerization and isoform specificity redefine mitochondrial function as a signaling hub

For decades, the voltage-dependent anion-selective channel (VDAC), or mitochondrial porin, was viewed as a simple pore enabling passive permeability across the outer mitochondrial membrane. This limited perspective overlooked its complex roles in cellular physiology. The discovery of three mammalian isoforms (VDAC1, VDAC2, VDAC3) and their diverse functions beyond metabolite exchange highlighted a critical gap in understanding how VDAC contributes to mitochondrial connectivity and overall cellular health. Unraveling VDAC's true nature is crucial for addressing diseases linked to mitochondrial dysfunction.

This review synthesizes recent structural, functional, and pharmacological advances in VDAC biology, driven by breakthroughs in cryo-electron microscopy. Researchers have elucidated high-resolution structures of VDAC within its native protein complexes, revealing its intricate architecture. They've also uncovered unexpected functions, such as phospholipid scrambling and the regulation of outer membrane permeabilization through higher-order oligomeric assemblies. Furthermore, structural determination of VDAC interactions with macromolecules and small-molecule modulators has provided a comprehensive view of its dynamic behavior and regulatory mechanisms.

Recent research has fundamentally reshaped the understanding of VDAC, moving beyond its traditional role as a simple pore. The discovery of three mammalian isoforms (VDAC1, VDAC2, VDAC3) has revealed distinct cellular roles. High-resolution cryo-electron microscopy has provided unprecedented insights into VDAC's structure within native protein complexes. This has led to the identification of unexpected functions, including its involvement in phospholipid scrambling and the regulation of outer membrane permeabilization via higher-order oligomeric assemblies.

These converging lines of evidence collectively establish VDAC as a multifunctional signaling hub, orchestrating mitochondrial behavior through its oligomerization dynamics and isoform specificity.