1. Calcium- and Nitric Oxide-Dependent Nuclear Accumulation of Cytosolic Glyceraldehyde-3-Phosphate Dehydrogenase in Response to Long Chain Bases in Tobacco BY-2 Cells.
- Author
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Testard A, Da Silva D, Ormancey M, Pichereaux C, Pouzet C, Jauneau A, Grat S, Robe E, Brière C, Cotelle V, Mazars C, and Thuleau P
- Subjects
- Amino Acid Sequence, Cell Nucleus drug effects, Cytosol drug effects, Genes, Plant, Glyceraldehyde-3-Phosphate Dehydrogenases chemistry, Glyceraldehyde-3-Phosphate Dehydrogenases genetics, Mass Spectrometry, Mutation genetics, Nitrosation, Nucleic Acids metabolism, Plant Cells drug effects, Plant Proteins chemistry, Plant Proteins genetics, Plant Proteins metabolism, Protein Binding drug effects, Sphingosine pharmacology, Nicotiana enzymology, Nicotiana genetics, Calcium pharmacology, Cell Nucleus enzymology, Cytosol enzymology, Glyceraldehyde-3-Phosphate Dehydrogenases metabolism, Nitric Oxide pharmacology, Plant Cells enzymology, Sphingosine analogs & derivatives, Nicotiana cytology
- Abstract
Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid long chain bases (LCBs) in plants, is known to induce a calcium-dependent programmed cell death (PCD) in plants. In addition, in tobacco BY-2 cells, it has been shown that DHS triggers a rapid production of H
2 O2 and nitric oxide (NO). Recently, in analogy to what is known in the animal field, plant cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC), a ubiquitous enzyme involved in glycolysis, has been suggested to fulfill other functions associated with its oxidative post-translational modifications such as S-nitrosylation on cysteine residues. In particular, in mammals, stress signals inducing NO production promote S-nitrosylation of GAPC and its subsequent translocation into the nucleus where the protein participates in the establishment of apoptosis. In the present study, we investigated the behavior of GAPC in tobacco BY-2 cells treated with DHS. We found that upon DHS treatment, an S-nitrosylated form of GAPC accumulated in the nucleus. This accumulation was dependent on NO production. Two genes encoding GAPCs, namely Nt(BY-2)GAPC1 and Nt(BY-2)GAPC2, were cloned. Transient overexpression of Nt(BY-2)GAPC-green fluorescent protein (GFP) chimeric constructs indicated that both proteins localized in the cytoplasm as well as in the nucleus. Mutating into serine the two cysteine residues thought to be S-nitrosylated in response to DHS did not modify the localization of the proteins, suggesting that S-nitrosylation of GAPCs was probably not necessary for their nuclear relocalization. Interestingly, using Förster resonance energy transfer experiments, we showed that Nt(BY-2)GAPCs interact with nucleic acids in the nucleus. When GAPCs were mutated on their cysteine residues, their interaction with nucleic acids was abolished, suggesting a role for GAPCs in the protection of nucleic acids against oxidative stress., (© The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.)- Published
- 2016
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