Import of phosphatidylinositol and phosphatidylcholine into mitochondria of the yeast, Saccharomyces cerevisiae.

An in vitro assay was designed to study the import of 3H-labeled phosphatidylinositol and phosphatidylcholine, respectively, from unilamellar vesicles into isolated mitochondria of the yeast, Saccharomyces cerevisiae. Both phospholipids reached the inner mitochondrial membrane. During import they were detected in contact sites between the outer and the inner mitochondrial membrane, supporting the notion that these zones are sites of intramitochondrial phospholipid transport. The uncoupler CCCP, the antibiotic adriamycin, and energy depletion caused by oligomycin and apyrase did not inhibit the transport of phosphatidylinositol and phosphatidylcholine into mitochondria.