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08:05
Assaying Protein Kinase Activity with Radiolabeled ATP
Published on: May 26, 2017
PKA-mediated protein phosphorylation regulates ezrin-WWOX interaction
Changjiang Jin1, Ling Ge, Xia Ding
1Laboratory of Cellular Dynamics, University of Science and Technology of China, Heifei National Laboratory for Physical Sciences at the Microscale, Hefei 230027, China.
Biochemical and Biophysical Research Communications
|January 28, 2006
Summary
Phosphorylation of ezrin by protein kinase A (PKA) regulates its interaction with WWOX, which is crucial for apical membrane remodeling and HCl secretion in gastric parietal cells.
Area of Science:
- Cell biology
- Molecular biology
- Biochemistry
Background:
- Ezrin-radixin-moesin (ERM) proteins link membrane proteins to the cytoskeleton and are involved in signal transduction.
- Ezrin localizes to the apical membrane of gastric parietal cells, coupling protein kinase A (PKA) activation to HCl secretion.
- Previous work identified Ser(66) as the PKA phosphorylation site on ezrin, but the regulatory mechanism remained unclear.
Purpose of the Study:
- To investigate the molecular basis of PKA-mediated ezrin regulation in gastric parietal cells.
- To elucidate the interaction between ezrin and WWOX and its role in parietal cell function.
Main Methods:
- Biochemical assays to study ezrin-WWOX interaction.
- Mutational analysis to identify key residues in the interaction.
- Immunofluorescence microscopy to assess protein localization.
Main Results:
- PKA-mediated phosphorylation of ezrin at Ser(66) regulates its interaction with WWOX via ezrin's C-terminal polyproline sequence (470)PPPPPPVY(477).
- Tyrosine(477) of ezrin is essential for WWOX binding.
- PKA phosphorylation of ezrin is necessary and sufficient for apical localization of WWOX, and disruption of this interaction prevents it.
- The ezrin-WWOX interaction is critical for apical membrane remodeling and H,K-ATPase recruitment.
Conclusions:
- PKA-mediated phosphorylation of ezrin at Ser(66) is a key regulatory event.
- This phosphorylation controls ezrin's interaction with WWOX, influencing WWOX localization.
- The ezrin-WWOX complex plays a vital role in apical membrane remodeling and gastric acid secretion.
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