Voltage-gated ion channels; Structure, Function, Regulation and Mechanisms

The main goal of my research is to shed light on the molecular mechanisms that control electrical signaling in the brain.
In particular, I am interested in voltage-gated potassium channels, which are directly responsible for the regulation of electrical activity in the nervous system of primitive organisms and humans. My laboratory applies state-of-the-art technology to investigate two specific areas.

Gating of a neuronal shock-absorber: Voltage-gated potassium channels (Kv4) absorb the nerve impulse as it attempts to propagate back into the dendrites of nerve cells. In this area, we are investigating the conformational changes that underlie gating of Kv4 channels. Our findings have shown that these channels employ novel mechanisms to autoregulate their activity and that specific accessory subunits, zinc and nitric oxide play critical roles. Current efforts are aimed at solving the molecular basis of these mechanisms.

General anesthetic sites in potassium channels: Alcohol and general anesthetics affect brain activity by interacting with a variety of neuronal ion channels. In another area, my laboratory investigates the structural basis of alcohol and general anesthetic action. By exploiting a neuronal potassium channel (Shaw-2) as a model system, we have determined that general anesthetic agents regulate function by a direct interaction with the channel's activation gate.

We are now focused on mapping the molecular determinants and interactions at the site of action in the channel protein. These investigations apply the following methodologies: patch-clamp electrophysiology; kinetic analysis and computer modeling; genetic engineering; substituted cysteine accessibility method; heterologous expression; protein biochemistry; primary neuronal culture; RT-PCR.

The outcome of our research will help neuroscientists to gain insights into the molecular basis of learning, memory, hyperexcitability disorders, general anesthesia and alcohol intoxication.