Abstract: Methods for identifying compounds that modulate the ion channel activity of a Kir channel are provided. Methods for identifying compounds that selectively modulate the ion channel activity of specific types of Kir channels based on the turret region of a Kir channel are also provided. Methods for identifying compounds to treat conditions associated with abnormal ion channel activity are also provided. Compounds including purified antibodies and methods of making antibodies which bind to the turret region of a Kir channel are provided. Purified polypeptides including at least a portion of the turret region of a Kir channel and nucleic acid sequences encoding these polypeptides are also provided.