Tafazzins from Drosophila and mammalian cells assemble in large protein complexes with a short half-life

• Tafazzin binds to multiple protein complexes in mitochondria and microsomes of Drosophila.
• Tafazzin binds to multiple protein complexes in mitochondria of mammalian cells.
• Tafazzin has a short half-life.

Tafazzin is a transacylase that affects cardiolipin fatty acid composition and mitochondrial function. Mutations in human tafazzin cause Barth syndrome yet the enzyme has mostly been characterized in yeast. To study tafazzin in higher organisms, we isolated mitochondria from Drosophila and mammalian cell cultures. Our data indicate that tafazzin binds to multiple protein complexes in these organisms, and that the interactions of tafazzin lack strong specificity. Very large tafazzin complexes could only be detected in the presence of cardiolipin, but smaller complexes remained intact even upon treatment with phospholipase A2. In mammalian cells, tafazzin had a half-life of only 3–6 h, which was much shorter than the half-life of other mitochondrial proteins. The data suggest that tafazzin is a transient resident of multiple protein complexes.