Mutations in nature conferred a high affinity phosphatidylinositol 4,5-bisphosphate-binding site in vertebrate inwardly rectifying potassium channels

Abstract

Background: A native Kir channel in a distant relative of vertebrates interacts weakly with PIP2. Results: Mutagenesis restores the vertebrate channel sensitivity to PIP2 in sponge channels. Conclusion: A basic residue in the tether helix of Kir is required for high affinity PIP2 regulation. Significance: Evolution conferred a high affinity interaction of vertebrate Kir channels with PIP2, which is lacking in a distant relative.