Implications of the O-GlcNAc modification in the regulation of nuclear apoptosis in T cells
| Autor: | Bruno Johnson, Jacques Bernier, Marlyse Opimba |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Cell signaling
Glycosylation Population Blotting Western Biophysics Phenylcarbamates Apoptosis N-Acetylglucosaminyltransferases Biochemistry O-Linked β-N-acetylglucosamine Acetylglucosamine Transcription (biology) Oximes Cytotoxic T cell Humans Immunoprecipitation Leukemia-Lymphoma Adult T-Cell Electrophoresis Gel Two-Dimensional Myocytes Cardiac education Molecular Biology Caspase Cell Nucleus education.field_of_study biology Cell Cycle Proteins Molecular biology Cell biology biology.protein DNA fragmentation Trialkyltin Compounds Apoptosis Regulatory Proteins Protein Processing Post-Translational Signal Transduction |
| Zdroj: | Biochimica et biophysica acta. 1840(1) |
| ISSN: | 0006-3002 |
| Popis: | Background O-linked β-N-acetylglucosamine (O-GlcNAc) is a nutrient-/stress-sensitive post-translational modification that affects nucleocytoplasmic proteins. The enzyme O-N-acetylglucosamine transferase (OGT) catalyzes the addition of O-GlcNAc, whereas O-N-acetylglucosaminidase (OGA) removes it. O-GlcNAcylation plays a role in fundamental regulatory mechanisms through the modification of proteins involved in cell division, metabolism, transcription, cell signaling and apoptosis. The effects of O-GlcNAcylation on apoptosis appear to be cell-dependent, as elevated levels played a protective role in primary neonatal rat ventricular myocytes but had a cytotoxic effect in rat pancreatic β-cells. The aim of the current study was to determine the implications of the O-GlcNAc modification on T cell apoptosis. Methods Human T lymphoblastic HPB-ALL cells were treated with the OGA inhibitor O-(2-acetamido-2-deoxy- d -glucopyranosylidene) amino-N-phenylcarbamate (PUGNAc), or with glucosamine (GlcN), to increase O-GlcNAcylation. Apoptosis was induced in the presence of tributyltin (TBT). DNA fragmentation was observed by cell cycle analysis and corresponded to the sub G0/G1 population. O-GlcNAcylated proteins were detected by immunoblot using a specific antibody (ctd110.6) and were precipitated using succinylated wheat germ agglutinin (sWGA). Results HPB-ALL cells treated with PUGNAc displayed a significant reduction in DNA fragmentation after TBT-induced apoptosis. DFF45, the protein that inhibits the endonuclease DFF40, was identified to be O-GlcNAc modified. O-GlcNAcylated DFF45 appeared to be more resistant to caspase cleavage during apoptosis. Our results suggest that a decrease in the O-GlcNAc modification on DFF45 occurs before its cleavage by caspase. General significance Our results indicate that the O-GlcNAcylation of DFF45 may represent a mechanism to control the accidental activation of DFF. |
| Databáze: | OpenAIRE |
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