Mitochondrial VDAC can be phosphorylated by cyclic AMP-dependent protein kinase.

The voltage dependent anion channel (VDAC) of the outer membrane of mitochondria is thought to play a role in transport of metabolites including ATP across mitochondrial membrane and modulate mitochondrial functions such as respiration. However, regulation of this anion channel is only poorly understood. In this paper we demonstrate that VDAC purified from rat liver mitochondria can be phosphorylated by the catalytic subunit of cAMP dependent protein kinase (PKA). PKA phosphorylates VDAC linearly up to fifteenfold in sixty minutes. The level of VDAC phosphorylation increases to twofold and sevenfold of control value after ten and thirty minutes of reaction, respectively. Data presented here suggest the possibility that voltage dependent anion channel of the outer membrane of mitochondria may be a target of PKA in vivo.