| Autor: |
Athwal GS; US Department of Agriculture, Department of Horticultural Science, North Carolina State University, Raleigh 27695, USA., Lombardo CR, Huber JL, Masters SC, Fu H, Huber SC |
| Jazyk: |
angličtina |
| Zdroj: |
Plant & cell physiology [Plant Cell Physiol] 2000 Apr; Vol. 41 (4), pp. 523-33. |
| DOI: |
10.1093/pcp/41.4.523 |
| Abstrakt: |
The proteins commonly referred to as 14-3-3s have recently come to prominence in the study of protein:protein interactions, having been shown to act as allosteric or steric regulators and possibly scaffolds. The binding of 14-3-3 proteins to the regulatory phosphorylation site of nitrate reductase (NR) was studied in real-time by surface plasmon resonance, using primarily an immobilized synthetic phosphopeptide based on spinach NR-Ser543. Both plant and yeast 14-3-3 proteins were shown to bind the immobilized peptide ligand in a Mg2+-stimulated manner. Stimulation resulted from a reduction in KD and an increase in steady-state binding level (Req). As shown previously for plant 14-3-3s, fluorescent probes also indicated that yeast BMH2 interacted directly with cations, which bind and affect surface hydrophobicity. Binding of 14-3-3s to the phosphopeptide ligand occurred in the absence of divalent cations when the pH was reduced below neutral, and the basis for enhanced binding was a reduction in K(D). At pH 7.5 (+Mg2+), AMP inhibited binding of plant 14-3-3s to the NR based peptide ligand. The binding of AMP to 14-3-3s was directly demonstrated by equilibrium dialysis (plant), and from the observation that recombinant plant 14-3-3s have a low, but detectable, AMP phosphatase activity. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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