Cardiolipin remodeling by TAZ/tafazzin is selectively required for the initiation of mitophagy.
Tafazzin (TAZ) is a phospholipid transacylase that catalyzes the remodeling of cardiolipin, a mitochondrial phospholipid required for oxidative phosphorylation. Mutations of TAZ cause Barth syndrome, which is characterized by mitochondrial dysfunction and dilated cardiomyopathy, leading to premature death. However, the molecular mechanisms underlying the cause of mitochondrial dysfunction in Barth syndrome remain poorly understood. Here we investigated the role of TAZ in regulating mitochondrial function and mitophagy. Using primary mouse embryonic fibroblasts (MEFs) with doxycycline-inducible knockdown of Taz, we showed that TAZ deficiency in MEFs caused defective mitophagosome biogenesis, but not other autophagic processes. Consistent with a key role of mitophagy in mitochondria quality control, TAZ deficiency in MEFs also led to impaired oxidative phosphorylation and severe oxidative stress. Together, these findings provide key insights on mitochondrial dysfunction in Barth syndrome, suggesting that pharmacological restoration of mitophagy may provide a novel treatment for this lethal condition.
a Department of Cellular and Molecular Physiology ; Hershey , PA USA.
Paul
P
Hsu
Xiaolei
X
Liu
Jun
J
Zhang
Hong-Gang
HG
Wang
Ji-Ming
JM
Ye
Yuguang
Y
Shi
D000217:Acyltransferases; D000818:Animals; D001343:Autophagy / Q000235:genetics / Q000502:physiology*; D002308:Cardiolipins / Q000378:metabolism*; D002311:Cardiomyopathy, Dilated / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006801:Humans; D051379:Mice; D008928:Mitochondria / Q000235:genetics; D063306:Mitophagy / Q000502:physiology*; D009154:Mutation / Q000235:genetics; D014157:Transcription Factors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
D002308:Cardiolipins; D014157:Transcription Factors; D000217:Acyltransferases; C486363:tafazzin protein, mouse; C108675:TAFAZZIN protein, human
AdGFP-LC3, recombinant adenovirus expressing GFP tagged MAP1LC3B; AdTAZ, recombinant adenovirus expressing Myc-tagged TAZ; BTHS, Barth syndrome; BafA1, bafilomycin A1; Barth syndrome; CCCP, carbonyl cyanide m-chlorophenylhydrazone; CL, cardiolipin; Dox, doxycycline; FCCP, carbonyl cyanide p-triflouromethoxyphenylhydrazone; LTG, LysoTracker Green; MAP1LC3B/LC3B, microtubule-associated protein 1 light chain 3 beta; MEF, mouse embryonic fibroblast; MLCL, monolysocardiolipin; MTR, MitoTracker Red; PARK2, parkin RBR E3 ubiquitin protein ligase; PINK1, PTEN-induced putative kinase 1; SOD2, superoxide dismutase 2 mitochondrial; TAZ, tafazzin; TLCL, tetralinoleoyl-cardiolipin; autophagy; cardiolipin; mitochondrial dysfunction; mitophagosome; mitophagy; tafazzin