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A Faster, High Resolution, mtPA-GFP-based Mitochondrial Fusion Assay Acquiring Kinetic Data of Multiple Cells in Parallel Using Confocal Microscopy
Published on: July 20, 2012
Mitochondria-type GPAT is required for mitochondrial fusion
Yohsuke Ohba1, Takeshi Sakuragi, Eriko Kage-Nakadai
1Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan.
The EMBO Journal
|April 11, 2013
Summary
Mitochondrial glycerol-3-phosphate acyltransferase (Mt-GPAT) is crucial for mitochondrial fusion. Its depletion causes fragmentation, but this can be rescued by lysophosphatidic acid (LPA) or by manipulating fusion/fission proteins.
Area of Science:
- Cell Biology
- Biochemistry
- Genetics
Background:
- Glycerol-3-phosphate acyltransferase (GPAT) initiates glycerolipid synthesis.
- GPAT exists in both endoplasmic reticulum (ER) and mitochondrial (Mt) forms.
- Distinct functions of ER-GPAT and Mt-GPAT remain unclear.
Purpose of the Study:
- To investigate the specific role of mitochondrial GPAT (Mt-GPAT) in cellular processes.
- To elucidate the function of Mt-GPAT beyond its role in lipid synthesis.
Main Methods:
- Generated GPAT mutants in C. elegans.
- Utilized C. elegans and HeLa cells for mitochondrial fusion assays.
- Employed genetic manipulation (inhibition/overexpression) of key mitochondrial dynamics proteins (DRP-1, FZO-1).
- Administered lysophosphatidic acid (LPA) and inhibited LPA acyltransferase to assess rescue effects.
Main Results:
- Mt-GPAT is essential for mitochondrial fusion in C. elegans.
- Mt-GPAT mutation leads to excessive mitochondrial fragmentation.
- Lysophosphatidic acid (LPA) accumulation rescues mitochondrial fragmentation.
- Mitochondrial fragmentation is linked to the balance of mitochondrial fission and fusion proteins.
- Mt-GPAT depletion impairs mitochondrial fusion in HeLa cells.
Conclusions:
- Mt-GPAT plays a critical role in maintaining mitochondrial fusion.
- The product of Mt-GPAT, LPA, is essential for mitochondrial fusion, not just lipid synthesis.
- Mt-GPAT influences the mitochondrial fusion/fission balance.
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