RUI: Investigating Structure and Dynamic Properties of the Potassium Channel Accessory Protein, KCNE3

About This Grant

Membrane proteins are essential for the survival and function of living organisms. Protein-protein interactions are fundamental to many cellular processes. Cholesterol is a critical component of the biological membrane that can bind to proteins, modulating their function and altering the trafficking or sorting of membrane proteins between different organelles. Structural studies of membrane proteins and their associations are one of the final frontiers in biophysics and structural biology. This research project will address the urgent challenges associated with the biologically significant protein KCNE3 and its interaction with KCNQ1 by focusing on structural and dynamic properties of KCNE3 in a lipid bilayer membrane in the presence of cholesterol, as well as its interaction with KCNQ1. This project will also explore new structural biology approaches. Additionally, the research will support undergraduate and high-school student teaching and training. These students will be involved in both experimental and computational aspects of the project, gaining experience in science, technology, engineering and mathematics (STEM) research. Students will present their research findings at national and international scientific conferences. A teaching-level modern biophysics laboratory will be designed to complement and enhance educational facilities at Campbellsville University. A science workshop and outreach program developed under this project will help spread scientific awareness and promote informal discussions of this scientific work, as well as STEM education and training within the community. KCNQ1, a voltage-gated K+ channel expressed in various body tissues is modulated by the single transmembrane protein KCNE3. The interaction between KCNE3 and KCNQ1 creates voltage-independent channels within the physiological voltage range, playing a crucial role in regulating water and salt transport in several epithelial tissues. Animal plasma membrane contains 25 to 50 mol% cholesterol, which alters it biophysical properties and influences potassium channel function. Despite the clear biological importance, the interaction between KCNE3 and KCNQ1 remains poorly understood. The objective of this research project is to investigate the structural and dynamic properties of KCNE3/KCNQ1 complex embedded in lipid bilayers using electron paramagnetic resonance (EPR) spectroscopic techniques and molecular dynamics (MD) modeling. Additionally, the effect of cholesterol will be investigated by detecting side-chain dynamics of the protein and measuring short-to-medium range distances between strategically placed nitroxide spin labels on the protein. A structural model of the KCNE3/KCNQ1 complex in lipid bilayers will be developed based on EPR and MD data. This research addresses a current gap in the field and will lead to a fundamental understanding of the structure and function of potassium channels. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.