| Title | Cross-talk between GlcNAcylation and phosphorylation: site-specific phosphorylation dynamics in response to globally elevated O-GlcNAc. | | Author(s) | Wang Z, Gucek M, Hart GW | | Institution | Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA. | | Source | Proc Natl Acad Sci U S A 2008 Sep 16; 105(37):13793-8. | | MeSH | Acetylglucosamine
Acylation
Amino Acid Sequence
Animals
Blotting, Western
DNA-Binding Proteins
Imidazoles
Mass Spectrometry
Mice
NIH 3T3 Cells
Phosphopeptides
Phosphorylation
Proteomics
RNA-Binding Proteins
Substrate Specificity
Titanium
| | Abstract | Protein GlcNAcylation serves as a nutrient/stress sensor to modulate the functions of many nuclear and cytoplasmic proteins. O-GlcNAc cycles on serine or threonine residues like phosphorylation, is nearly as abundant, and functions, at least partially, via its interplay with phosphorylation. Here, we describe changes in site-specific phosphorylation dynamics in response to globally elevated GlcNAcylation. By combining sequential phospho-residue enrichment, iTRAQ labeling, and high throughput mass spectrometric analyses, phosphorylation dynamics on 711 phosphopeptides were quantified. Based upon their insensitivity to phosphatase inhibition, we conclude that approximately 48% of these phosphorylation sites were not actively cycling in the conditions of the study. However, increased GlcNAcylation influenced phosphate stoichiometry at most of the sites that did appear to be actively cycling. Elevated GlcNAcylation resulted in lower phosphorylation at 280 sites and caused increased phosphorylation at 148 sites. Thus, the cross-talk or interplay between these two abundant posttranslational modifications is extensive, and may arises both by steric competition for occupancy at the same or proximal sites and by each modification regulating the other's enzymatic machinery. The phosphoproteome dynamics presented by this large set of quantitative data not only delineates the complex interplay between phosphorylation and GlcNAcyation, but also provides insights for more focused investigations of specific roles of O-GlcNAc in regulating protein functions and signaling pathways. | | Language | eng | | Pub Type(s) | Journal Article
Research Support, N.I.H., Extramural
| | PubMed ID | 18779572 |
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