Our laboratory is interested in how the duration of intracellular signaling is controlled in neurons. Our model system is the mammalian retinal photoreceptor cell which signals the presence of light using a G protein cascade that results in a reduction of the cell's inward current. As long as the cascade remains activated, the light response persists, making deactivation essential for maintaining both the sensitivity and temporal resolution of vision. To study deactivation mechanisms, we use suction electrodes to record from intact photoreceptors in which the functions of various proteins have been specifically perturbed using gene-targeting techniques. The electrical recording allows us to analyze the cell's responses to flashes or steps of light quantitatively and in real time. From the changes in inward current, we can infer a great deal about the rates of the reactions that underly both the activation and deactivation of the response elicited from a single activated rhodopsin molecule. A second arm of the lab studies G protein signaling at synapses in acute retinal slices. By manipulating the duration of G protein signaling by genetic and pharmacological methods, we hope to better understand how the temporal regulation of these cascades regulate synaptic transmission and are modulated in a use-dependent manner.

Teaching Interests:
Cellular neurophysiology; signal transduction mechanisms

Courses Taught:
NPB/NSC 160
NSC 221

Publications:

Burns, M.E., Mendez, A., Chen, C.-K., Almuete, A., Quillinan, N., Simon, M.I., Baylor, D.A., and Chen, J. (2006). Deactivation of phosphorylated and nonphosphorylated rhodopsin by arrestin splice variants. J. Neurosci., 26, 1036-1044.

Moussaif, M.,Rubin, W.W., Kerov, V., Reh, R., Chen, D., Chen, C.-K., Hurley, J.B., Burns, M.E. and Artemyev, N.O. (2006). Phototransduction in a transgenic mouse model of Nougaret night blindness. J. Neurosci. 26, 6863-6872.

Krispel, C.K., Chen, D., Chen, Y-J., Melling, N., Martemyanov, K.A., Quillinan, N., Arshavsky, V.Y., Wensel, T.G., Chen, C.-K.*, and Burns, M.E.* (2006). RGS expression sets the duration of signaling in rod photoreceptors. Neuron 51, 409-416.

Chan, S., Rubin, W.W., Mendez, A., Liu, X., Song, X., Hanson, S.M., Craft, C.M., Gurevich, V.V., Burns, M.E.*, and Chen, J*. (2007). Functional comparisons of visual arrestins in rod photoreceptors of transgenic mice. Invest Ophthalmol Vis Sci. 48, 1968-75.

Krispel, C.M., Sokolov, M., Chen, Y.-M., Song, H., Herrmann, R., Arshavsky, V.Y. and Burns, M.E. (2007). Phosducin regulates the expression of transducin betagamma subunits in rod photoreceptors and does not contribute to phototransduction adaptation. J. Gen. Physiol. 130, 303-312.

Kerov, V., Rubin, W.W., Natochin, M., Melling, N.A., Burns, M.E. and Artemyev, N.O. (2007). N-terminal fatty acylation of transducin profoundly influences its localization and the kinetics of photoresponse in rods. J. Neurosci. 27, 10270-10277.

Lobanova, E.S., Finkelstein, S., Herrmann, R., Chen, Y.-M., Kessler, C., Michaud, N.A., Trieu, L.H., Strissel, K.J., Burns, M.E. and Arshavsky, V.Y. (2008). Transducingamma-subunit set expression levels of alpha- and beta-subunits and is crucial for rod viability. J. Neurosci. 28, 3510-20.

Martemyanov, K.A., Krispel, C.M., Lishko, P.V., Burns*, M.E., and Arshavsky*, V.Y. (2008). Functional comparison of RGS9 splice isoforms in a living cell. Proc. Natl. Acad. Sci.