NIMIGEAN LAB

CURRENT RESEARCH

Ion channels are ubiquitous proteins, vital to scores of cellular processes including cell membrane excitability and propagation of nervous stimuli. Structural defects within ion channel proteins alter channel function and in turn cause human disease.One area of interest in the lab is to investigate ion channel modulation by ligands using a prokaryotic homologue of cyclic nucleotide-gated channels. Prokaryotic proteins are more suitable candidates for biochemical manipulations and X-ray crystallography as they often express in larger quantities and are better behaved in isolation than their eukaryotic counterparts. Their function can be concomitantly studied using electrophysiological methods that involve current measurement through protein incorporated in planar lipid bilayers. We are also working towards novel structure determination by X-ray crystallography and electron microscopy.

Another area of interest is geared toward understanding the mechanism employed by channels to tailor ion transport through their pores in a manner that begets their physiological functions. Ion channels are in general nonlinear in their conduction properties such that the current flowing in one direction through the pore is usually not equal to the current flowing in the opposite direction (rectification). In the case of a subset of rectifying channels the mechanism of inward rectification, while still largely a mystery, is known to be independent of extrinsic factors. We are studying the mechanism of rectification using electrophysiological, structural and biochemical methods with both prokaryotic and eukaryotic channels that exhibit these properties.