1. Characterization of the interactions between Nedd4-2, ENaC, and sgk-1 using surface plasmon resonance.
- Author
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Asher C, Sinha I, and Garty H
- Subjects
- Amino Acid Motifs, Amino Acid Sequence, Animals, Endosomal Sorting Complexes Required for Transport, Epithelial Sodium Channels, Immediate-Early Proteins, Ligases metabolism, Mice, Molecular Sequence Data, Nedd4 Ubiquitin Protein Ligases, Protein Serine-Threonine Kinases metabolism, Recombinant Proteins chemistry, Sodium Channels metabolism, Surface Plasmon Resonance, Calcium-Binding Proteins, Ligases chemistry, Nuclear Proteins, Protein Serine-Threonine Kinases chemistry, Sodium Channels chemistry, Ubiquitin-Protein Ligases
- Abstract
Previous studies have characterized interactions between the ubiquitin ligase Nedd4-1 and the epithelial Na(+) channel (ENaC). Such interactions control the channel cell surface expression and activity. Recently, evidence has been provided that a related protein, termed Nedd4-2, is likely to be the true physiological regulator of the channel. Unlike Nedd4-1, Nedd4-2 also interacts with the aldosterone-induced channel activating kinase sgk-1. The current study uses surface plasmon resonance to quantify the binding of the four WW domains of Nedd4-2 to synthetic peptides corresponding to the PY motifs of ENaC and sgk-1. The measurements demonstrate that WW3 and WW4 are the only Nedd4-2 domains interacting with both ENaC and sgk-1 and that their binding constants are in the 1-6 microM range.
- Published
- 2003
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