Mitochondria-type GPAT is required for mitochondrial fusion

Yohsuke Ohba, Takeshi Sakuragi, Eriko Kage-Nakadai, Naoko H. Tomioka, Nozomu Kono, Rieko Imae, Asuka Inoue, Junken Aoki, Naotada Ishihara, Takao Inoue, Shohei Mitani, Hiroyuki Arai

Research output: Contribution to journalArticlepeer-review

39 Citations (Scopus)


Glycerol-3-phosphate acyltransferase (GPAT) is involved in the first step in glycerolipid synthesis and is localized in both the endoplasmic reticulum (ER) and mitochondria. To clarify the functional differences between ER-GPAT and mitochondrial (Mt)-GPAT, we generated both GPAT mutants in C. elegans and demonstrated that Mt-GPAT is essential for mitochondrial fusion. Mutation of Mt-GPAT caused excessive mitochondrial fragmentation. The defect was rescued by injection of lysophosphatidic acid (LPA), a direct product of GPAT, and by inhibition of LPA acyltransferase, both of which lead to accumulation of LPA in the cells. Mitochondrial fragmentation in Mt-GPAT mutants was also rescued by inhibition of mitochondrial fission protein DRP-1 and by overexpression of mitochondrial fusion protein FZO-1/mitofusin, suggesting that the fusion/fission balance is affected by Mt-GPAT depletion. Mitochondrial fragmentation was also observed in Mt-GPAT-depleted HeLa cells. A mitochondrial fusion assay using HeLa cells revealed that Mt-GPAT depletion impaired mitochondrial fusion process. We postulate from these results that LPA produced by Mt-GPAT functions not only as a precursor for glycerolipid synthesis but also as an essential factor of mitochondrial fusion.

Original languageEnglish
Pages (from-to)1265-1279
Number of pages15
JournalEMBO Journal
Issue number9
Publication statusPublished - 2013 May 2
Externally publishedYes


  • C. elegans
  • fusion
  • glycerol-3-phosphate acyltransferase
  • lysophosphatidic acid
  • mitochondria

ASJC Scopus subject areas

  • General Neuroscience
  • Molecular Biology
  • General Biochemistry,Genetics and Molecular Biology
  • General Immunology and Microbiology


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