HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 280, Issue 49, 41069-41076, December 9, 2005

This Article Full Text Full Text (PDF) All Versions of this Article: 280/49/41069    most recent M508849200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kerov, V. Articles by Artemyev, N. O. Search for Related Content PubMed PubMed Citation Articles by Kerov, V. Articles by Artemyev, N. O. Social Bookmarking                      What's this?

Transducin Activation State Controls Its Light-dependent Translocation in Rod Photoreceptors^*

Vasily Kerov, Desheng Chen, Mustapha Moussaif, Yu-Jiun Chen, Ching-Kang Chen, and Nikolai O. Artemyev1

From the Department of Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, Iowa 52242 and the Department of Biochemistry, Virginia Commonwealth University, Richmond, Virginia 23298

Light-dependent redistribution of transducin between the rod outer segments (OS) and other photoreceptor compartments including the inner segments (IS) and synaptic terminals (ST) is recognized as a critical contributing factor to light and dark adaptation. The mechanisms of light-induced transducin translocation to the IS/ST and its return to the OS during dark adaptation are not well understood. We have probed these mechanisms by examining light-dependent localizations of the transducin- subunit (Gt)in mice lacking the photoreceptor GAP-protein RGS9, or expressing the GTPase-deficient mutant GtQ200L. An illumination threshold for the Gt movement out of the OS is lower in the RGS9 knockout mice, indicating that the fast inactivation of transducin in the wild-type mice limits its translocation to the IS/ST. Transgenic GtQ200L mice have significantly diminished levels of proteins involved in cGMP metabolism in rods, most notably the PDE6 catalytic subunits, and severely reduced sensitivity to light. Similarly to the native Gt, the GtQ200L mutant is localized to the IS/ST compartment in light-adapted transgenic mice. However, the return of GtQ200L to the OS during dark adaptation is markedly slower than normal. Thus, the light-dependent translocations of transducin are controlled by the GTP-hydrolysis on Gt, and apparently, do not require Gt interaction with RGS9 and PDE6.

Received for publication, August 10, 2005 , and in revised form, October 3, 2005.

^* This work was supported by National Institutes of Health Grants EY12682 (to N. O. A.) and EY13811 (to C.-K. C.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ To whom correspondence should be addressed: Dept. of Physiology and Biophysics, University of Iowa College of Medicine, 5-532 Bowen Science Bldg., 51 Newton Rd., Iowa City, IA 52242. Tel.: 319-335-7864; Fax: 319-335-7330; E-mail: nikolai-artemyev{at}uiowa.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				V. Kerov, W. W. Rubin, M. Natochin, N. A. Melling, M. E. Burns, and N. O. Artemyev N-Terminal Fatty Acylation of Transducin Profoundly Influences Its Localization and the Kinetics of Photoresponse in Rods J. Neurosci., September 19, 2007; 27(38): 10270 - 10277. [Abstract] [Full Text] [PDF]

				C. M. Krispel, M. Sokolov, Y.-M. Chen, H. Song, R. Herrmann, V. Y. Arshavsky, and M. E. Burns Phosducin Regulates the Expression of Transducin {beta}{gamma} Subunits in Rod Photoreceptors and Does Not Contribute to Phototransduction Adaptation J. Gen. Physiol., August 27, 2007; 130(3): 303 - 312. [Abstract] [Full Text] [PDF]

				H. Song, M. Belcastro, E. J. Young, and M. Sokolov Compartment-specific Phosphorylation of Phosducin in Rods Underlies Adaptation to Various Levels of Illumination J. Biol. Chem., August 10, 2007; 282(32): 23613 - 23621. [Abstract] [Full Text] [PDF]

				D. Kalra, R. Elsaesser, Y. Gu, and K. Venkatachalam Transducin in Rod Photoreceptors: Translocated When Not Terminated J. Neurosci., June 13, 2007; 27(24): 6349 - 6351. [Full Text] [PDF]

				D. H. Rosenzweig, K. S. Nair, J. Wei, Q. Wang, G. Garwin, J. C. Saari, C.-K. Chen, A. V. Smrcka, A. Swaroop, J. Lem, et al. Subunit Dissociation and Diffusion Determine the Subcellular Localization of Rod and Cone Transducins J. Neurosci., May 16, 2007; 27(20): 5484 - 5494. [Abstract] [Full Text] [PDF]

				E. S. Lobanova, S. Finkelstein, H. Song, S. H. Tsang, C.-K. Chen, M. Sokolov, N. P. Skiba, and V. Y. Arshavsky Transducin Translocation in Rods Is Triggered by Saturation of the GTPase-Activating Complex J. Neurosci., January 31, 2007; 27(5): 1151 - 1160. [Abstract] [Full Text] [PDF]

				M. Moussaif, W. W. Rubin, V. Kerov, R. Reh, D. Chen, J. Lem, C.-K. Chen, J. B. Hurley, M. E. Burns, and N. O. Artemyev Phototransduction in a transgenic mouse model of Nougaret night blindness. J. Neurosci., June 21, 2006; 26(25): 6863 - 6872. [Abstract] [Full Text] [PDF]