Phosphatidic acid (PA) binds PP2AA1 to regulate PP2A activity and PIN1 polar localization
Hong-Bo Gao1, Yu-Jia Chu, Hong-Wei Xue
1National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese academy of Sciences, 200032 Shanghai, People's Republic of China.
Molecular Plant
|May 21, 2013
Summary
Phospholipase D (PLD) produces phosphatidic acid (PA), which regulates Protein Phosphatase 2A (PP2A) activity. This study reveals PA recruits PP2A to membranes, controlling auxin transport protein dephosphorylation in plants.
Area of Science:
- Plant Biology
- Molecular Cell Biology
- Biochemistry
Background:
- Phospholipase D (PLD) generates phosphatidic acid (PA), a lipid mediator involved in eukaryotic signaling.
- PA binds to and modulates the activity or localization of various proteins, including kinases and phosphatases.
- Protein Phosphatase 2A (PP2A) is a key phosphatase with crucial regulatory roles in animals and plants.
Purpose of the Study:
- To investigate the interaction between PLD-derived PA and PP2A in Arabidopsis.
- To elucidate the role of PA and PP2A in the regulation of PIN1 dephosphorylation and auxin distribution.
- To uncover the mechanism by which PA influences PP2A localization and activity.
Main Methods:
- Genetic analysis in Arabidopsis.
- Pharmacological treatments with PLD inhibitors.
- Biochemical assays to assess protein-protein interactions and enzyme activity.
- Microscopy to observe protein localization.
Main Results:
- PLD-derived PA interacts with the PP2A scaffolding subunit A1 (PP2AA1).
- PA and PP2A are involved in regulating auxin distribution via PIN1 dephosphorylation.
- PLD inhibition affects PIN1 phosphorylation and polar localization; exogenous PA promotes PP2AA1 membrane accumulation and PP2A activity.
Conclusions:
- PA recruits PP2AA1 to the membrane system, regulating PP2A function on membrane-associated proteins.
- PLD-derived PA is crucial for proper PP2A-mediated dephosphorylation of PIN1.
- This PA-mediated recruitment mechanism for PP2A is conserved and may operate in various eukaryotic biological processes.
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