Rod and cone photoreceptors in the eye have the daunting task of signaling the number and timing of photon absorptions across the 9 log units of light intensities encountered daily. Signaling over such a wide range of stimulus intensities requires dozens of specialized signaling molecules whose enzymatic activities are regulated in time. How the concerted action of these many regulators change during periods of light adaptation are not fully understood, but when they fail to work properly photoreceptors undergo degeneration and blindness results.
Using a combination of genetic engineering approaches, biochemistry, physiology and imaging we are investigating the time course of signaling in rod photoreceptors and how this signaling is modified during light adaptation and in response to the earliest stages of photoreceptor cell death. Specifically, we are now focused on the following questions:
- What are the biochemical reaction rates that dictate the sensitivity of rod signaling?
- What alters these reaction rates during light adaptation?
- What are the consequences for cellular signaling and synaptic transmission?
- How do defects in these reactions lead to photoreceptor degeneration?
For more information, please visit the Burns Lab website: http://burnslab.ucdavis.edu.
2012 Gross, O.P., Pugh, Jr. E.N. and Burns, M.E. Calcium feedback to cGMP synthesis more strongly attenuates single photon responses driven by long rhodopsin lifetimes. Neuron 76, 370–382.
2012 Gross, O.P., Pugh, Jr. E.N. and Burns, M.E. Spatiotemporal cGMP dynamics in living mouse rods. Biophys. J. 102, 1775-1784.
2012 Arshavsky, V.I. and Burns, M.E. Photoreceptor signaling: supporting vision across a wide range of light intensities. J. Biol. Chem. 287, 1620-6.
2010 Burns, M.E. and Pugh, Jr. E.N. Lessons from photoreceptors: Turning off G protein signaling in living cells. Physiology 25, 72-84.
2010 Gross, O.P. and Burns, M.E. Arrestin expression controls the duration of rhodopsin lifetime in intact rods. J. Neurosci. 30, 3450-7.
2010 Burns, M.E. Deactivation mechanisms of rod phototransduction: The Cogan Lecture. Invest Ophthalmol Vis Sci. 51, 1282-8.
2009 Burns, M.E. and Pugh, Jr. E.N. RGS9 concentration matters in rod phototransduction. Biophysical J. 97, 1538-1547.
2009 Song, X., Vishnivetskiy, S.A., Gross, O.P., Emelianoff, K., Mendez, A., Chen, J., Gurevich, E.V., Burns*, M.E., and Gurevich*, V.V. Enhanced arrestin mutant facilitates photoresponse recovery and protects rod photoreceptors in the absence of rhodopsin phosphorylation. Curr. Biol. 19, 700-5.
2008 Martemyanov, K.A., Krispel, C.M., Lishko, P.V., Yoo, P.J., Burns*, M.E. and Arshavsky, V.Y. Functional comparison of RGS9 splice isoforms in a living cell. Proc. Natl. Acad. Sci. 105, 20988-20933.
2006 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. RGS expression rate-limits recovery of rod photoresponses. Neuron 51, 409-416.
NPB221 / NSC221 Cellular Neuroscience
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Teaching and Research Awards
- 2013 - Outstanding Graduate Mentor in Neuroscience Award
- 2010 - Alumni Achievement Award, Susquehanna University
- 2009 - Kavli Fellow, National Academy of Sciences
- 2009 - Cogan Award, Association for Research in Vision and Ophthalmology
- 2002-2004 - Alfred P. Sloan Research Fellow
- 2002-2005 - E. Matilda Ziegler Foundation for the Blind Research Award