Depletion of voltage-dependent anion channel (VDAC) of Toxoplasma gondii affects multiple mitochondrial functions, but not calcium signalling.

Abstract

The Voltage Dependent Anion channel (VDAC) is a ubiquitous channel in the outer membrane of the mitochondrion with multiple roles in protein, metabolite and small molecule transport. In mammalian cells, VDAC, as part of a larger complex including the inositol triphosphate receptor, has been shown to have a role in mediating contact between the mitochondria and ER. We identify VDAC of the pathogenic apicomplexan Toxoplasma gondii and demonstrate its importance for parasite growth. We show that VDAC is involved in protein import and metabolite transfer to the mitochondria, but does not appear to modulate calcium (Ca2+) signalling. Further, depletion of VDAC resulted in significant morphological changes of the mitochondrion and ER, suggesting a role in mediating contacts between these organelles in T. gondii.