Department of Biochemistry

Maxim Sokolov, Ph.D.

Graduate Training:
Weizmann Institute of Science, Israel

Fellowships:
University of Kansas,
Harvard University/Massachusetts,
Eye and Ear Infirmary

Assistant Professor
Departments of Ophthalmology,
Biochemistry
Sensory Neuroscience Research Center
West Virginia University School of Medicine
West Virginia University Eye Institute
One Stadium Drive P.O. Box 9193
Morgantown, WV 26506-9193
Phone: 304-598-6958
Fax: 304-598-6928
Email: sokolovm@rcbhsc.wvu.edu

Research Interests:

My laboratory studies G protein mediated signaling in the retina photoreceptors, highly specialized neurons responsible for acquisition of visual information. My research program addresses the fundamental, yet poorly understood mechanisms that govern synthesis, delivery, and degradation of signaling proteins in neurons. Our multi-tiered experimental approach offers an exciting opportunity to master a variety of techniques including antibody-based protein recognition, confocal fluorescence microscopy, real-time PCR and gene arrays, mass spectrometry, and transgenics.

Research Topics

Phosducin Biochemistry

The role of phosducin in regulation of G protein mediated signaling in photoreceptors

Phosducin is an abundant photoreceptor-specific 33kD protein that forms a complex with the betagamma subunit of transducin, a central heterotrimeric G protein of visual cascade. Phosducin belongs to the family of phosducin-like proteins, which are ubiquitously expressed and essential for cell survival. The function of phosducin and phosducin-like proteins remains largely unknown. Previously we demonstrated that the knockout of phosducin gene resulted in the substantial down regulation of transducin expression in photoreceptors (Sokolov et al., 2004). Our next goal is to understand the mechanism of the observed down-regulation that will provide clues to the general mechanisms regulating G protein expression in the cell. In order to elucidate the role of phosducin in regulating day/night activity of photoreceptors, we will study light-dependent phosphorylation of phosducin, which governs its interaction with G proteins.

Lab Personnel

Marycharmain Belcastro
Senior Research Specialist
Phone: 304-598-4746
Email: mbelcastro@hsc.wvu.edu

Hongman Song
Graduate Student
Phone: 304-598-4745
Email: hsong4@mix.wvu.edu

Recent publications:

• Krispel CM, Sokolov M, Chen YM, Song H, Herrmann R, Arshavsky VY, Burns ME.  Phosducin regulates the expression of transducin betagamma subunits in rod photoreceptors and does not contribute to phototransduction adaptation.  Journal of General Physiology (2007), 130(3):303-312.
   
• Song H, Belcastro M, Young EJ, Sokolov M.  Compartment-specific phosphorylation of phosducin in rods underlies adaptation to various levels of illumination.  Journal of Biological Chemistry (2007), 282(32):23613-23621.
   
• Song JH, Song H, Wensel TG, Sokolov M, Martemyanov KA.  Localization and differential interaction of R7 RGS proteins with their membrane anchors R7BP and R9AP in neurons of vertebrate retina.  Molecular and Cellular Neuroscience (2007), 35(2):311-319.
   
• Lobanova ES, Finkelstein S, Song H, Tsang SH, Chen CK, Sokolov M, Skiba NP, Arshavsky VY.  Transducin translocation in rods is triggered by saturation of the GTPase-activating complex. Journal of Neuroscience (2007) 27(5):1151-1160.
   
• Boesze-Battaglia K, Song H, Sokolov M, Lillo C, Pankoski-Walker L, Gretzula C, Gallagher B, Rachel RA, Jenkins NA, Copeland NG, Morris F, Jacob J, Yeagle P, Williams DS, Damek-Poprawa M.  The tetraspanin protein peripherin-2 forms a complex with melanoregulin, a putative membrane fusion regulator.  Biochemistry, (2007) 46(5):1256-1272.
   
• Strissel KJ, Sokolov M, Trieu LH, Arshavsky VY. Arrestin translocation is induced at a critical threshold of visual signaling and is superstoichiometric to bleached rhodopsin. Journal of Neuroscience (2006), 26(4):1146-1153.
   
• Sokolov M, Strissel KJ, Leskov IB, Michaud NA, Govardovskii VI, Arshavsky VY. Phosducin facilitates light-driven transducin translocation in rod photoreceptors: evidence from the phosducin knockout mouse. Journal of Biological Chemistry (2004), 279(18):19149-19156.
   
• Hong DH, Pawlyk B, Sokolov M, Strissel KJ, Yang J, Tulloch B, Wright AF, Arshavsky VY, Li T. RPGR isoforms in photoreceptor connecting cilia and the transitional zone of motile cilia. Investigative Ophthalmology and Visual Science (2003), 44(6):2413-2421.
   
• Martemyanov KA, Lishko PV, Calero N, Keresztes G, Sokolov M, Strissel KJ, Leskov IB, Hopp JA, Kolesnikov AV, Chen CK, Lem J, Heller S, Burns ME, Arshavsky VY. The DEP domain determines subcellular targeting of the GTPase activating protein RGS9 in vivo. Journal of Neuroscience (2003), 23(32):10175-10181.
   
• Sokolov M, Lyubarsky AL, Strissel KJ, Savchenko AB, Govardovskii VI, Pugh EN Jr, Arshavsky VY. Massive light-dependent translocation of transducin between the functional compartments of rod photoreceptors: a novel mechanism of light adaptation. Neuron (2002), 34(1):95–106.