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Proteomics to Identify Proteins Interacting with P2X2 Ligand-Gated Cation Channels
Published on: May 18, 2009
Glycosylation regulates pannexin intermixing and cellular localization
Silvia Penuela1, Ruchi Bhalla, Kakon Nag
1Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario N6A 5C1, Canada.
Molecular Biology of the Cell
|August 21, 2009
Summary
Mammalian pannexins (Panx1, Panx2, Panx3) form functional cell surface channels. Their interactions and glycosylation regulate channel function and cellular distribution.
Area of Science:
- Cellular Biology
- Molecular Biology
- Protein Interactions
Background:
- Pannexins (Panx1, Panx2, Panx3) are a family of mammalian proteins.
- They are proposed as single-membrane channels with similarities to connexins.
- Their functional roles and regulation are not fully understood.
Purpose of the Study:
- To investigate interactions among pannexin family members.
- To determine the role of glycosylation in pannexin trafficking and function.
- To elucidate how pannexin interactions affect channel activity.
Main Methods:
- Immunolabeling and coimmunoprecipitation assays were used to study protein interactions.
- Biotinylation and dye uptake assays assessed cell surface trafficking and channel function.
- N-glycosylation-defective mutants were employed to examine glycosylation's role.
Main Results:
- Panx1 interacts with Panx2 and Panx3 in a glycosylation-dependent manner.
- All three pannexins traffic to the cell surface and form functional channels.
- Panx2 cell surface abundance increases with Panx1 coexpression, but Panx1/Panx2 coexpression compromises channel function.
Conclusions:
- Pannexin functional state and distribution are regulated by glycosylation.
- Interactions between pannexin family members modulate their cellular behavior.
- These findings provide insights into pannexin channel regulation.
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