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Nuclear Magnetic Resonance Spectroscopy for the Identification of Multiple Phosphorylations of Intrinsically Disordered Proteins
Published on: December 27, 2016
Does prothymosin alpha affect the phosphorylation of elongation factor 2?
S A Enkemann1, K S Pavur, A G Ryazanov
1Section on Genes and Gene Products, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA.
The Journal of Biological Chemistry
|June 22, 1999
Summary
Prothymosin alpha does not directly affect eukaryotic elongation factor 2 (eEF-2) phosphorylation. A previously reported activation was likely an artifact caused by fluoride, a phosphatase inhibitor.
Area of Science:
- Molecular Biology
- Cell Biology
Background:
- Prothymosin alpha is an essential nuclear protein involved in cell proliferation and survival.
- Previous research suggested prothymosin alpha increases eukaryotic elongation factor 2 (eEF-2) phosphorylation.
Purpose of the Study:
- To investigate the proposed role of prothymosin alpha in eEF-2 phosphorylation.
- To validate or refute the findings of Vega et al. regarding prothymosin alpha's effect on eEF-2.
Main Methods:
- Utilized NIH3T3 cell lysates prepared via four different methods.
- Tested native and recombinant prothymosin alpha preparations.
- Employed a reconstituted system with eEF-2, eEF-2 kinase, calmodulin, and calcium.
- Evaluated the impact of fluoride, a phosphatase inhibitor, on phosphorylation.
Main Results:
- Failed to observe any increase in eEF-2 phosphorylation in response to prothymosin alpha.
- The reconstituted system remained unaffected by prothymosin alpha.
- Fluoride significantly reduced phosphorylation, and its reduced effective concentration mimicked activation.
Conclusions:
- The data do not support a direct functional relationship between prothymosin alpha and eEF-2 phosphorylation.
- The previously reported activation effect is likely an artifact due to fluoride inhibition of phosphatases.
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