Phosphatidic Acid Binds to Cytosolic Glyceraldehyde-3-phosphate Dehydrogenase and Promotes Its Cleavage in Arabidopsis

• Published in: The Journal of biological chemistry 2013-04, Vol.288 (17), p.11834-11844
• Main Authors: Kim, Sang-Chul, Guo, Liang, Wang, Xuemin
• Format: Article
• Language: English
• Subjects: Arabidopsis; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Carbohydrate Metabolism - physiology; catalysis (homogeneous), catalysis (heterogeneous), solar (fuels), photosynthesis (natural and artificial), biofuels (including algae and biomass), bio-inspired, charge transport, carbon capture, synthesis (novel materials); Cell Signaling; Cytoplasm - enzymology; Cytoplasm - genetics; Glyceraldehyde-3-phosphate Dehydrogenase; Glyceraldehyde-3-Phosphate Dehydrogenases - genetics; Glyceraldehyde-3-Phosphate Dehydrogenases - metabolism; Lipid Metabolism; Lipid Metabolism - physiology; Lipid Signaling; Lipid-binding Protein; Lipids; Phosphatidic Acid; Phosphatidic Acids - genetics; Phosphatidic Acids - metabolism; Plant Biochemistry; Proteolysis; Seedlings - enzymology; Seedlings - genetics; Seedlings - growth & development; Zinc; Zinc - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M112.427229

Phosphatidic acid (PA) is a class of lipid messengers involved in a variety of physiological processes. To understand how PA mediates cell functions in plants, we used a PA affinity membrane assay to isolate PA-binding proteins from Camelina sativa followed by mass spectrometric sequencing. A cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC) was identified to bind to PA, and detailed analysis was carried out subsequently using GAPC1 and GAPC1 from Arabidopsis. The PA and GAPC binding was abolished by the cation zinc whereas oxidation of GAPCs promoted the PA binding. PA had little impact on the GAPC catalytic activity in vitro, but the PA treatment of Arabidopsis seedlings induced proteolytic cleavage of GAPC2 and inhibited Arabidopsis seedling growth. The extent of PA inhibition was greater in GAPC-overexpressing than wild-type seedlings, but the greater PA inhibition was abolished by application of zinc to the seedling. The PA treatment also reduced the expression of genes involved in PA synthesis and utilization, and the PA-reduced gene expression was partially recovered by zinc treatment. These data suggest that PA binds to oxidized GAPDH and promotes its cleavage and that the PA and GAPC interaction may provide a signaling link coordinating carbohydrate and lipid metabolism. Background: Phosphatidic acid (PA) is a class of membrane lipid mediators synthesized in response to various stresses in plants. Results: PA binds to cytosolic glyceraldehyde-3-phosphate dehydrogenases (GAPCs) and promotes proteolytic cleavage of GAPC2 in Arabidopsis. Conclusion: PA-GAPC interaction constitutes a mechanism for PA signaling in plants. Significance: PA-GAPC interaction may provide a molecular link modulating coordinately carbohydrate and lipid metabolism.