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Crina Nimigean

Assistant Professor
cnimigean@ucdavis.edu


Physiology and Membrane Biology

Office
4220 TUPPER HALL
530 754 7660

Lab
530 754 8538



Degrees:

1999 PhD University of Miami School of Medicine Physiology and Biophysics

Research Interests:


Research in our laboratory is geared towards understanding how ion channel protein structure and mechanism interrelate at the molecular level to allow channels to elaborate various biological properties. A combination of molecular, biochemical and electrophysiological approaches allows us to evaluate in a complete fashion fundamental channel properties within the context of emerging structural data. 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. Current work in our lab involves two main areas: 1) We are currently investigating 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 approaching novel structure determination by X-ray crystallography and electron microscopy in collaboration with Tina Iverson at Vanderbilt University and Henning Stahlberg at UC Davis. 2) Another project in the lab is geared towards 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). This asymmetry, crucial to the channels physiological function in cells, is due to factors either extrinsic or intrinsic to the channel protein. In the case of a subset of rectifying channels the mechanisms of inward rectification, while still largely a mystery, are known to be independent of such extrinsic factors. We are studying the mechanism of rectification by making use of a prokaryotic and a eukaryotic channel. Using the information garnered from electrophysiological studies from both channels, coupled with known structural parameters for the prokaryotic channel, a comprehensive picture of K channel rectification can be made.





Awards:

Scientist Development Award - American Heart Association 2006-2010

Professional Societies:

Biophysical Society
Society for Neuroscience

Publications:

Last updated 5/21/2010
Crina M. Nimigean (2006). A radioactive uptake assay for the measurement of ion transport across ion channel-containing liposomes. Nature Protocols, 1.3:1207-1212. Invited protocol.
 

Zadek B. and Nimigean C.M. (2006). Calcium dependent gating of MthK, a prokaryotic potassium channel. Journal of General Physiology, 127:673-685
 

Nimigean C.M., Shane T., and Miller, C (2004). A cyclic nucleotide modulated prokaryotic K+ channel. Journal of General Physiology, 124:203-210 (Accompanied by commentary)
 

Nimigean, C.M, Chappie, J.S. and Miller, C (2003). Electrostatic tuning of ion conductance in potassium channels. Biochemistry, 42:9263-9268
 

Qian X, Nimigean CM, Niu X, Moss BL, Magleby KL (2002). Slo1 tail domains, but not the Ca2+ bowl, are required for the beta1 subunit to increase the apparent Ca2+ sensitivity of BK channels. Journal of General Physiology, 120:829-43.
 

Nimigean, C.M and Miller, C. (2002). Na+ block and permeation in a K+ channel of known structure. Journal of General Physiology, 120:323-335
 

Nimigean, C.M. and Magleby, K.L. (2000). Functional coupling of the b1 subunit to the large conductance Ca2+-activated K+ channel in the absence of Ca2+. Increased Ca2+ sensitivity from a Ca2+-independent mechanism. Journal of General Physiology, 115:719-734
 

Moss, B.L., Silberberg, S.D., Nimigean, C.M. and Magleby, K.L. (1999). Ca2+-dependent gating mechanisms for dslo, a large conductance Ca2+-activated K+ (BK) channel. Biophysical Journal, 76:3099-3117
 

Nimigean, C.M. and Magleby, K.L. (1999). The b subunit increases the Ca2+-sensitivity of large conductance Ca2+-activated potassium channels by retaining the gating in the bursting states. Journal of General Physiology, 113:425-439
 

Brett, C.M.A. and Nimigean, C.M. (1997). Corrosion of sputtered W--Ni--N hard coatings in chloride media. Thin Solid Films, 311 (1-2):1-6
 


Laboratory Personnel:

4205, 4207 Tupper Hall

Ameer Thompson-Graduate Student;
Matthew Pagel-Laboratory Assistant;
Niloofar Zabihi-Laboratory Assistant;
Pirooz Parsa-Laboratory Assistant




Courses:

MCP 210 Membrane Biophysics Fall
MCB 241 X-Ray Crystallography of Membrane Proteins Spring