InterPro domain: IPR000872

This entry includes tafazzin and its homologues, such as Taz1 from yeasts and N-acylphosphatidylethanolamine synthase from plants. Tafazzin is an enzyme involved in the cardiolipin remodelling pathway [ 1 , 2 ]. The phospholipid cardiolipin is an important component of the inner mitochondrial membrane that is involved in mitochondrial energy production and apoptosis [ 3 ].

In humans tafazzin is expressed at high levels in cardiac and skeletal muscle. As many as 10 isoforms can be present in different amounts in different tissues. Isoforms with hydrophobic N-termini are thought to be membrane anchored, while shorter forms, lacking the hydrophobic stretch, may be cytoplasmic (these latter are found in leukocytes and fibroblasts, but not in heart and skeletal muscle). A central hydrophilic domain may serve as an exposed loop that interacts with other proteins. Defects in the taz gene are the cause of Barth syndrome, a severe inherited disorder, often fatal in childhood. The disease is characterised by cardiac and skeletal myopathy, short stature and neutropenia [ 3 ].

In flies tafazzin is a CoA-independent, acyl-specific phospholipid transacylase with substrate preference for cardiolipin and phosphatidylcholine [ 4 ].

Budding yeast Taz1 is a lyso-phosphatidylcholine acyltransferase that is required for normal phospholipid content of mitochondrial membranes, whose acyl specificity in the reaction relies on lipid chemical composition [ 5 , 6 ].

Arabidopsis N-acylphosphatidylethanolamine synthase (NAPE synthase, At1g78690) is an acyltransferase that catalyses the N-acylation of phosphatidylethanolamine to form N-acylphosphatidylethanolamine (N-acyl-PE) [ 7 ].

1. Role of calcium-independent phospholipase A2 in the pathogenesis of Barth syndrome. Proc. Natl. Acad. Sci. U.S.A. 106, 2337-41
2. The enigmatic role of tafazzin in cardiolipin metabolism. Biochim. Biophys. Acta 1788, 2003-14
3. A novel X-linked gene, G4.5. is responsible for Barth syndrome. Nat. Genet. 12, 385-9
4. The enzymatic function of tafazzin. J. Biol. Chem. 281, 39217-24
5. Ypr140wp, 'the yeast tafazzin', displays a mitochondrial lysophosphatidylcholine (lyso-PC) acyltransferase activity related to triacylglycerol and mitochondrial lipid synthesis. Biochem. J. 387, 617-26
6. The Basis for Acyl Specificity in the Tafazzin Reaction. J Biol Chem 292, 5499-5506
7. Putative N-acylphosphatidylethanolamine synthase from Arabidopsis thaliana is a lysoglycerophospholipid acyltransferase. J. Biol. Chem. 286, 33819-31