Dr. Sun-Joo Lee receives AHA Fellowship Award.

Congratulation to Sun-Joo for being awarded a one-year American Heart Association Fellowship Award!

Project Title: "Kir Channel Gating by Membrane Lipid Binding"
Award Period: 1/01/15 - 12/31/15

Summary: Ion channels are critical to control membrane potentials, to transduce information across plasma membranes, and are likely affected by altered lipid populations. Inwardly rectifying potassium (Kir) channels are important for a cardiac function. Lipid molecules in cell membranes are critical regulators for ion channels, and their sustained asymmetric distribution between the two phospholipid monolayers is critical for normal cell physiology. Phosphati dyl (4,5)bisphosphate (PIP2), bulk anionic phospoholipids, and cholesterol are the known regulatory lipids that directly bind to the Kir2 subfamily, influencing channel activity. The goal of this study is to unambiguously elucidate the functional changes of Kir2 channels when combined with different regulatory lipids. Utilizing synthetic proteoliposomes that allow for the tight control of lipid compositions in the liposomes, the investigator will elucidate interplay among the regulatory lipids controlling these channels. In addition, She will implement a cutting-edge method with which ion channel activity can be measured in asymmetric membranes, which are more similar to physiological conditions. The proposed research will clarify how changes in lipid compositions in cell membranes may affect ion channel activities in more physiologically relevant environments and also give mechanistic insights into their regulation through direct binding to the channels.