MD, University of Missouri-Columbia School of Medicine
Department: Pharmacological and Physiological Science
Academic Rank: Assistant Professor
Phone: 314-977-6353 Fax: 314-977-6410
Lab Web Page Links:
Primary Area of Cardiovascular Research Interest
-Structure/function of ion channels, with a particular focus on inward rectifier potassium channels.
Related Areas of Cardiovascular Research Interest
-Lipid regulation of ion channels. Diabetes. Renal disease.
Summary of Cardiovascular Research Interest
My lab focuses on the biology of ion channels, with a current emphasis on the structural mechanisms of ligand gating in inwardly rectifying potassium (Kir) channels. Mutations of ion channels are associated with a wide variety of human diseases, and in the Kir channel family alone, mutations that alter responsiveness to ligands are known causes of diverse diseases including diabetes, hyperinsulinism, cardiac arrhythmias, seizure disorders, developmental disorders, and derangement of salt homeostasis. We use the bacterial potassium channel, KirBac1.1, as a model Kir channel. Purified KirBac1.1 protein has been shown to form potassium selective channels, and shares many characteristics with eukaryotic Kirs including block by barium, and regulation by protons and membrane lipids (such as PIP2). This lab uses a combination of techniques in studying KirBac1.1, including the rubidium uptake assay using purified channel protein reconstituted into liposomes, patch clamp recordings of KirBac channels from giant liposomes, and structural analysis through crystallization and electron paramagnetic resonance (EPR) of KirBac protein. The cytoplasmic domain of eukaryotic Kirs is thought to contain the binding sites of many of the known regulatory ligands. The location of these binding sites, and the structural mechanisms underlying transduction of this binding signal to a gate located in the transmembrane domains remains unclear. Using the above techniques, this lab is interested in proton and membrane lipid modulation of KirBac1.1 channel activity, with the ultimate goal of understanding the structural changes associated with opening and closing of the channel gating in response to these ligands. Knowledge of the structural mechanisms underlying modulation of KirBac1.1 channel activity by ligands can provide insights into eukaryotic Kir gating in general, and potentially provide broad patterns of channel domain movements associated not only with lipid and proton gating, but of ligand gating of ion channels in general.